package/libcamera: disable werror

package/libcamera: disable werror

This will fix the following build failure:

../src/gstreamer/gstlibcameraallocator.cpp: In static member function 'static GQuark FrameWrap::getQuark()':
/home/peko/autobuild/instance-1/output-1/host/x86_64-buildroot-linux-gnu/sysroot/usr/include/glib-2.0/glib/gatomic.h:128:15: error: variable 'gapg_temp_atomic' set but not used [-Werror=unused-but-set-variable]
     gpointer *gapg_temp_atomic = (gpointer *)(atomic);                       \
               ^

Fixes:
 - http://autobuild.buildroot.org/results/c28500d4cc55fbd2bac87f2c11759ddc9163bc91

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>