Re-allow user_catalog_table option for materialized views.

The reloptions stuff allows this option to be set on a matview.
While it's questionable whether that is useful or was really intended,
it does work, and we shouldn't change that in minor releases.  Commit
e3e66d8a disabled the option since I didn't realize that it was
possible for it to be set on a matview.  Tweak the test to re-allow it.

Discussion: <19749.1478711862@sss.pgh.pa.us>

src/include/utils/rel.h

@@ -270,8 +270,9 @@ typedef struct StdRdOptions
  *		from the pov of logical decoding.  Note multiple eval of argument!
  */
 #define RelationIsUsedAsCatalogTable(relation)	\
-	((relation)->rd_rel->relkind == RELKIND_RELATION && \
-	 (relation)->rd_options ? \
+	((relation)->rd_options && \
+	 ((relation)->rd_rel->relkind == RELKIND_RELATION || \
+	  (relation)->rd_rel->relkind == RELKIND_MATVIEW) ? \
 	 ((StdRdOptions *) (relation)->rd_options)->user_catalog_table : false)
 
 /*