The interfaces main loop repeats the select() (non-blocking) after an
event was handled.  I do not see any reason for that, since all events
should be handled after the first select().  This double select() does
nothing than consume more CPU cycles.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7213 09075e82-0dd4-0310-85a5-a0d7c8717e4f