Fixed failed test on Oracle.

Changed on 'cancel': In oracle message contain word 'cancel'(ORA-01013: user requested cancel of current operation) and not 'cancelled' or 'canceled'. Word 'cancel' contains in message for all database types.

Author: Vyacheslav

src/NHibernate.Test/Stateless/StatelessSessionCancelQueryFixture.cs

@@ -83,8 +83,7 @@ private void CancelQueryTest(Action<IStatelessSession> queryAction)
 					s2.CancelQuery();
 					Assert.That(() => queryTask,
 						Throws.InnerException.TypeOf(typeof(OperationCanceledException))
-							.Or.InnerException.Message.Contains("cancelled")
-							.Or.InnerException.Message.Contains("canceled"));
+							.Or.InnerException.Message.Contains("cancel"));
 				}
 			}
 		}