Fix warnings in logs

[notartom]

Turning on CodeIgniter logging in config.php spams the following. They don't appear to affect anything, but are still annoying when trying to find actual errors in the logs.

artom@librivox:/librivox/www/librivox.org/catalog$ cut -d\  -f9- application/logs/log-2022-12-27.php  | sort -u
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 18
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 26
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 34
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 50
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 59
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 67
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 75
Trying to access array offset on value of type null /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 91
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 18
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 26
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 34
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 50
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 59
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 67
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 75
Undefined variable $advanced_search_form /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 91
Undefined variable $advanced_search /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 2
Undefined variable $genres /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 59
Undefined variable $project /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 27
Undefined variable $project /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 30
Undefined variable $project /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 33
Undefined variable $project /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 44
Undefined variable $project /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 47
Undefined variable $project /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 50
Undefined variable $project /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 53
Undefined variable $project_type /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 75
Undefined variable $recorded_languages /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 83
Undefined variable $sort_order /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 91
Undefined variable $statuses /librivox/www/librivox.org/catalog/application/views/catalog/partials/advanced_search.php 67
Undefined variable $volunteers /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 56
Undefined variable $volunteers /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 59
Undefined variable $volunteers /librivox/www/librivox.org/catalog/application/views/catalog/partials/book_sidebar.php 62