Handle MySQL default value particularity in test

Though MySQL min datetime value is 1000-01-01, if default value for column
is true dotnet min value, the RDBMS doesn't rewrite it with true min value

Author: alex-kulakov

Orm/Xtensive.Orm.Tests/Storage/TypeCompatibilityTest.cs

@@ -284,7 +284,10 @@ public void DefaultValuesTest()
           Assert.AreEqual(false, x.FBool);
           Assert.AreEqual(0, x.FByte);
           Assert.AreEqual(null, x.FByteArray);
-          Assert.AreEqual(minValue, x.FDateTime);
+          if (StorageProviderInfo.Instance.CheckProviderIs(StorageProvider.MySql))
+            Assert.AreEqual(DateTime.MinValue, x.FDateTime);
+          else
+            Assert.AreEqual(minValue, x.FDateTime);
           Assert.AreEqual(0, x.FDecimal);
           Assert.AreEqual(0, x.FDouble);
           Assert.AreEqual(EByte.Default, x.FEByte);