PulseAudio's GTK+ support is limited to a test case and automatic icon name
population for applications. This is too limited to enforce GTK+ 3 on all
builds, so disable it by default.
(From OE-Core rev: 619e63946fef32995363981aab288fc669e8ac04)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>