Fixing missing initializer for field in gscanner.c

glib/gscanner.c:344:1: error: missing initializer for field ‘padding_dummy’ of ‘GScannerConfig’ {aka ‘const struct _GScannerConfig’} [-Werror=missing-field-initializers]
 };
 ^
In file included from glib/gscanner.c:40:
glib/gscanner.h:166:10: note: ‘padding_dummy’ declared here
   guint  padding_dummy;
          ^~~~~~~~~~~~~

glib/gscanner.c

@@ -341,6 +341,7 @@ static const GScannerConfig g_scanner_config_template =
   FALSE			/* symbol_2_token */,
   FALSE			/* scope_0_fallback */,
   FALSE			/* store_int64 */,
+  0    			/* padding_dummy */
 };