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.
(cherry picked from commit 048b787961492e2f1da6e426385659a773a84395)