Remove unnecessary row ordering dependency in pg_rewind test suite.

t/002_databases.pl was expecting to see a specific physical order of the
rows in pg_database.  I broke that in HEAD with commit 01e386a325549b77,
but I'd say it's a pretty fragile test methodology in any case, so fix
it in 9.5 as well.

src/bin/pg_rewind/t/002_databases.pl

@@ -32,13 +32,13 @@ sub run_test
 
 	# Check that the correct databases are present after pg_rewind.
 	check_query(
-		'SELECT datname FROM pg_database',
-		qq(template1
-template0
-postgres
+		'SELECT datname FROM pg_database ORDER BY 1',
+		qq(beforepromotion
 inmaster
-beforepromotion
+postgres
 standby_afterpromotion
+template0
+template1
 ),
 		'database names');