fix: config fetcher called twice

[voslartomas]

Motivation and Context

Config fetcher Subscribe method was called twice, because of init config channel, therefore it was calling 2 requests to control panel at the same time (also logging twice, that is how I noticed).

Logs

{"level":"debug","time":1701182852460,"caller":"controlplane/configfetcher.go:85","msg":"No new router config available, received nil router config, trying again in 10 seconds","hostname":"cosmo-router-7598cf9d5b-6wbmt","pid":1,"component":"@wundergraph/router","service_version":"0.39.0"}
{"level":"debug","time":1701182852523,"caller":"controlplane/configfetcher.go:85","msg":"No new router config available, received nil router config, trying again in 10 seconds","hostname":"cosmo-router-7598cf9d5b-6wbmt","pid":1,"component":"@wundergraph/router","service_version":"0.39.0"}
{"level":"debug","time":1701182853064,"caller":"controlplane/configfetcher.go:85","msg":"No new router config available, received nil router config, trying again in 10 seconds","hostname":"cosmo-router-7598cf9d5b-6wbmt","pid":1,"component":"@wundergraph/router","service_version":"0.39.0"}

Notice mainly first two logs called almost at the same time

Plus small fix to logs to include pollInterval instead of hardcoded value as it can be changed.

• Tests or benchmark included
• Documentation is changed or added on https://app.gitbook.com/
• PR title must follow conventional-commit-standard

[StarpTech]

Hi @voslartomas, thank you for the PR. We did a refactoring in #318 which addresses the issue.