build: bump GLib required version to 2.34

Commit 7ea3203f uses g_clear_pointer
that was added in glib 2.34:
glib@00285b75

!10 (comment 600118)

configure.ac

@@ -147,7 +147,7 @@ AC_SUBST(XLIB_LIBS)
 
 PKG_CHECK_MODULES([LIBWNCK],[
 	gtk+-3.0 >= 3.22.0
-	glib-2.0 >= 2.32
+	glib-2.0 >= 2.34
 	gobject-2.0 >= 2.13.0
 	$CAIRO_XLIB_XRENDER_PACKAGE
 	$STARTUP_NOTIFICATION_PACKAGE

meson.build

@@ -40,7 +40,7 @@ XRES_PACKAGE = 'xres'
 
 pkg_deps = [
   {'name': 'cairo-xlib-xrender', 'required': false},
-  {'name': 'glib-2.0', 'version': '>= 2.32' },
+  {'name': 'glib-2.0', 'version': '>= 2.34' },
   {'name': 'gobject-2.0', 'version': '>= 2.13.0' },
   {'name': 'gtk+-3.0', 'version': '>= 3.22.0' },
   {'name': STARTUP_NOTIFICATION_PACKAGE, 'version': '>= 0.4', 'required': get_option('startup_notification')},