psql: Make EXECUTE PROCEDURE tab completion a bit narrower.

If the user has typed GRANT EXECUTE, the correct completion is "ON",
not "PROCEDURE".

Daniel Verite

src/bin/psql/tab-complete.c

@@ -2622,6 +2622,7 @@ psql_completion(const char *text, int start, int end)
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views, NULL);
 	/* complete CREATE TRIGGER ... EXECUTE with PROCEDURE */
 	else if (pg_strcasecmp(prev_wd, "EXECUTE") == 0 &&
+			 !(pg_strcasecmp(prev2_wd, "GRANT") == 0 && prev3_wd[0] == '\0') &&
 			 prev2_wd[0] != '\0')
 		COMPLETE_WITH_CONST("PROCEDURE");