Fix bug with second training with no changes causing error

Author: pbrownMW

+ic/Model.m

@@ -339,7 +339,7 @@ function train(this)
             % preprocessing
             this.TrainingOptions.ValidationData = ...
                 augmentedImageDatastore(networkInputSize(1:2), ...
-                this.TrainingOptions.ValidationData, ...
+                this.ValidationData, ...
                 colorPreprocessing=colorPreprocessing);
 
             [this.TrainedNetwork, this.TrainingResults] = trainnet( ...

test/unit/tModel.m

@@ -204,7 +204,7 @@ function canSetTrainingOptions(test)
             test.verifyEqual(model.TrainingOptions.MaxEpochs, 17);
         end
 
-        function trainsNetworK(test)
+        function trainsNetwork(test)
             % We should be able to train the network.
 
             model = test.createSpecimen();
@@ -219,6 +219,22 @@ function trainsNetworK(test)
             test.verifyNotEmpty(model.TrainedNetwork);
         end
 
+        function secondTrainingSuccessful(test)
+            % Training the model twice with no setting changes should work
+            % as intended.
+
+            model = test.createSpecimen();
+            test.importTestData(model);
+            model.setAugmentations(RandRotation=[-5 5]);
+            model.setNetworkFromPretrained("squeezenet");
+            test.configureModelForFastTraining(model);
+
+            model.train();
+            model.train();
+
+            test.verifyNotEmpty(model.TrainedNetwork);
+        end
+
         function predictsOnImage(test)
             % We should be able to perform inference on a single new image.