Buildbot: Disable QuickTime for the time being

Buildbot machine was updated to the new SDK which seems to have
QTKit removed.

For until we've installed older SDK or ported our code to a new
AVFramework disabling QuickTime.

build_files/buildbot/slave_compile.py

@@ -74,6 +74,7 @@ if 'cmake' in builder:
             cmake_extra_options.append('-DCMAKE_OSX_ARCHITECTURES:STRING=x86_64')
         cmake_extra_options.append('-DCUDA_NVCC_EXECUTABLE=/usr/local/cuda-hack/bin/nvcc')
         cmake_extra_options.append('-DCUDA_NVCC8_EXECUTABLE=/usr/local/cuda8-hack/bin/nvcc')
+        cmake_extra_options.append('-DWITH_CODEC_QUICKTIME=OFF')
 
     elif builder.startswith('win'):
         if builder.endswith('_vc2015'):