Cdn qps default

[sxci]

变更背景描述

当前 master qps 参数为 0， size 参数为 0 ，小于 1 表示参数无效，
此次更改设置默认值： qps 1 ， 目录刷新 size 为 9 ，具体url 刷新、预取 szie 为 59
https://developer.qiniu.com/fusion/api/1227/file-prefetching
https://developer.qiniu.com/fusion/api/1229/cache-refresh

jira issue链接

https://jira.qiniu.io/browse/TS-1029

主要变更点

• []fix bug
• [v]new feature
• []不兼容变更

Checklist

• [v] 已自测
• [] 已更新Readme

[qiniu-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bachue, sxci

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [bachue,sxci]

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[codecov]

Codecov Report

Merging #287 (de9f03b) into master (2ab8bc4) will decrease coverage by 0.37%.
The diff coverage is 25.00%.

Additional details and impacted files

@@            Coverage Diff            @@
##           master    #287      +/-   ##
=========================================
- Coverage    6.76%   6.40%   -0.37%     
=========================================
  Files          40      40              
  Lines        4876    4464     -412     
=========================================
- Hits          330     286      -44     
+ Misses       4540    4173     -367     
+ Partials        6       5       -1     

Impacted Files	Coverage Δ
cmd/cdn.go	8.33% <25.00%> (-0.76%)	⬇️

... and 39 files with indirect coverage changes