community/snapcast: Fix random crashes due to regexp parsing

Replaces regexp parsing with simple string compares to avoid snapcast to sporadically crash when used with librespot as the audio stream source.

The issue is described here: https://github.com/badaix/snapcast/issues/1026

Upstream patch used: https://github.com/badaix/snapcast/commit/4907fb42af822b0c0a07b885cda137b6f30a54fa