fix to remove warning on postgres adapter test.

Warning was: "/vagrant/rails/activerecord/test/cases/adapters/postgresql/uuid_test.rb:63:
warning: ambiguous first argument; put parentheses or even spaces"

activerecord/test/cases/adapters/postgresql/uuid_test.rb

@@ -60,7 +60,7 @@ def test_pk_and_sequence_for_uuid_primary_key
   def test_schema_dumper_for_uuid_primary_key
     schema = StringIO.new
     ActiveRecord::SchemaDumper.dump(@connection, schema)
-    assert_match /\bcreate_table "pg_uuids", id: :uuid\b/, schema.string
+    assert_match(/\bcreate_table "pg_uuids", id: :uuid\b/, schema.string)
   end
 end