update to latest gtk-osx master (newer automake)

Author: elelay

bootstrap.sh

@@ -15,7 +15,7 @@ mkdir -p "$HOME/.config"
 cp misc/jhbuildrc-custom "$HOME/.config/jhbuildrc-custom"
 git clone  https://gitlab.gnome.org/GNOME/gtk-osx.git _gtk-osx
 # try latest commit
-(cd _gtk-osx && git checkout f899bfcb)
+(cd _gtk-osx && git checkout 357671e5)
 # fix boostrap failure: error message on pip download
 sed -i '' s,https://bootstrap.pypa.io/2.7/get-pip.py,https://bootstrap.pypa.io/pip/2.7/get-pip.py, _gtk-osx/gtk-osx-setup.sh
 yes | ./_gtk-osx/gtk-osx-setup.sh