coregrilo: Do not search online sources by default

On search Grilo would search online sources by default as well. This is
unwanted as it is a privacy issue.

Currently Music has no UI to enable/disable this by user request, go the
safe route and disable it for stable release.

Closes #317
4 jobs for wip/mschraal/grilo-disable-online-search-3-34 in 24 minutes and 59 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Check
passed #494427
flake8

00:04:08

 
  Build Flatpak
passed #494428
flatpak

00:14:05

 
  Deploy
passed #494429
review

00:03:28

passed #494430
allowed to fail manual
stop_review

00:03:16