build: also suppress unused-function warnings about g_autoptr

../plugins/ges/gesdemux.c:50:1: error: unused function 'glib_autoptr_cleanup_GESDemux' [-Werror,-Wunused-function]
G_DECLARE_FINAL_TYPE (GESDemux, ges_demux, GES, DEMUX, GESBaseBin);
^
/home/matt/Projects/cerbero/build/dist/android_universal/x86_64/include/glib-2.0/gobject/gtype.h:1401:3: note: expanded from macro 'G_DECLARE_FINAL_TYPE'
  _GLIB_DEFINE_AUTOPTR_CHAINUP (ModuleObjName, ParentName)                                               \
  ^
/home/matt/Projects/cerbero/build/dist/android_universal/x86_64/include/glib-2.0/glib/gmacros.h:451:22: note: expanded from macro '_GLIB_DEFINE_AUTOPTR_CHAINUP'
  static inline void _GLIB_AUTOPTR_FUNC_NAME(ModuleObjName) (ModuleObjName **_ptr) {                     \
                     ^
/home/matt/Projects/cerbero/build/dist/android_universal/x86_64/include/glib-2.0/glib/gmacros.h:441:43: note: expanded from macro '_GLIB_AUTOPTR_FUNC_NAME'
#define _GLIB_AUTOPTR_FUNC_NAME(TypeName) glib_autoptr_cleanup_##TypeName
                                          ^
<scratch space>:81:1: note: expanded from here
glib_autoptr_cleanup_GESDemux
^

../plugins/ges/gessrc.c:56:1: error: unused function 'glib_autoptr_cleanup_GESSrc' [-Werror,-Wunused-function]
G_DECLARE_FINAL_TYPE (GESSrc, ges_src, GES, SRC, GESBaseBin);
^
/home/matt/Projects/cerbero/build/dist/android_universal/x86_64/include/glib-2.0/gobject/gtype.h:1401:3: note: expanded from macro 'G_DECLARE_FINAL_TYPE'
  _GLIB_DEFINE_AUTOPTR_CHAINUP (ModuleObjName, ParentName)                                               \
  ^
/home/matt/Projects/cerbero/build/dist/android_universal/x86_64/include/glib-2.0/glib/gmacros.h:451:22: note: expanded from macro '_GLIB_DEFINE_AUTOPTR_CHAINUP'
  static inline void _GLIB_AUTOPTR_FUNC_NAME(ModuleObjName) (ModuleObjName **_ptr) {                     \
                     ^
/home/matt/Projects/cerbero/build/dist/android_universal/x86_64/include/glib-2.0/glib/gmacros.h:441:43: note: expanded from macro '_GLIB_AUTOPTR_FUNC_NAME'
#define _GLIB_AUTOPTR_FUNC_NAME(TypeName) glib_autoptr_cleanup_##TypeName
                                          ^
<scratch space>:158:1: note: expanded from here
glib_autoptr_cleanup_GESSrc
^
20 jobs for master in 63 minutes and 10 seconds (queued for 24 seconds)
Status Job ID Name Coverage
  Preparation
passed #545106
gst indent

00:00:19

passed #545105
manifest

00:00:34

 
  Build
passed #545116
build cerbero android universal

00:11:27

passed #545117
build cerbero cross win32

00:10:03

passed #545118
build cerbero cross win64

00:07:00

passed #545115
build cerbero fedora x86_64

00:06:21

manual #545120
gst-ios-12.2 allowed to fail manual
build cerbero ios universal
passed #545119
gst-macos-10.14
build cerbero macos x86_64

00:08:23

passed #545111
build clang fedora x86_64

00:07:12

passed #545107
build fedora x86_64

00:07:34

passed #545114
docker windows 1607
build msys2

00:14:03

passed #545108
build nodebug fedora x86_64

00:07:31

passed #545109
build static fedora x86_64

00:14:46

passed #545110
build static nodebug fedora x86_64

00:13:08

passed #545112
docker windows 1607
build vs2017 amd64

00:11:00

passed #545113
docker windows 1607
build vs2017 x86

00:10:13

 
  Test
passed #545121
check fedora

00:04:01

passed #545122
integration testsuites fedora

00:15:19

 
  Integrate
passed #545123
android universal examples

00:09:24

passed #545124
documentation

00:04:55