Fix timeout-related regression in core.discover

Fixes a bug forcing the timeout of the discover function to be 100ms
Merge pull request #244 from hkhanna/discover-timeout-fix

Fix timeout-related regression in core.discover.
Revert f26f2357ab6e6a0286557784c03e0b3801ebd7df
Merge remote-tracking branch 'upstream/master' into get-album-art-uri