Bump catversion for pg_stat_wal changes.

Oversight in 01469241.

Reported-by: Andres Freund
Discussion: https://postgr.es/m/20201207185614.zzf63vggm5r4sozg@alap3.anarazel.de

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202011251
+#define CATALOG_VERSION_NO	202012081
 
 #endif