Update glib to 2.50 to fix build with gcc 10
* Makefile.am: Update patches. (gpg4win_pkg_glib_configure): Add CFLAGS required for newer gcc versions. * src/gpg4win.mk.in: Explicitly add -fcommon to CFLAGS. * packages/packages.current (glib): Update * patches/glib: Use packages from MXE.
This brings our glib build in line with the MXE packages
so we need not much to care about this and can reuse their
patches.