Fix dbz possibility with small buffers at end of track

There was a possibility of a dbz when a buffer sent to the
analyzer was shorter than 1ms long, such as what may happen at the end
of a track when stopping. This patch guards against this.
Merge branch 'master' of https://github.com/TheUbuntuGuy/Clementine
Merge pull request #4353 from TheUbuntuGuy/master

Fix dbz possibility with small buffers at end of track