macosx: disable the libsamplerate plugin by default to save 5 to 11 per cent...

macosx: disable the libsamplerate plugin by default to save 5 to 11 per cent of CPU load on an i5 when playing ordinary stereo audio (AAC, 128kb/s)

the performance impact is even more noticeble on older CPUs of course

extras/package/macosx/configure.sh

@@ -22,6 +22,7 @@ OPTIONS="
         --disable-skins2
         --disable-xcb
         --disable-sdl
+        --disable-samplerate
 "
 
 sh "$(dirname $0)"/../../../configure ${OPTIONS} $*