m4: Fix AM_PATH_GLIB_2_0 macro
There's an extraneous variable expansion in the pkg-config check for GLib which breaks the check and makes it fail every time.
This breaks every Autotools-based module using AM_PATH_GLIB_2_0.
There's an extraneous variable expansion in the pkg-config check for GLib which breaks the check and makes it fail every time.
This breaks every Autotools-based module using AM_PATH_GLIB_2_0.