mpd 0.24 aborts in main() when /proc/self/status reports more than one
thread, before it even parses the command line (src/Main.cxx). qemu-user
always reports several, so "mpd --version" cannot run on the emulated CI
targets and the generic version check fails there.
Add test-version.sh matching the version string compiled into the
binary, and drop the two unusable "mpd --version" calls from test.sh,
whose failures it silently ignored anyway.
Signed-off-by: Alexandru Ardelean <alex@shruggie.ro>