one more new line

Added another new line character since that is how the save dirty scene looks like

com.unity.shadergraph/Editor/Drawing/MaterialGraphEditWindow.cs

             if (graphObject != null)
             {
                 string nameOfFile = AssetDatabase.GUIDToAssetPath(selectedGuid);
-                if (graphObject.isDirty && EditorUtility.DisplayDialog("Shader Graph Has Been Modified", "Do you want to save the changes you made in the shader graph?\n" + nameOfFile + "\nYour changes will be lost if you don't save them.", "Save", "Don't Save"))
+                if (graphObject.isDirty && EditorUtility.DisplayDialog("Shader Graph Has Been Modified", "Do you want to save the changes you made in the shader graph?\n" + nameOfFile + "\n\nYour changes will be lost if you don't save them.", "Save", "Don't Save"))
                     UpdateAsset();
                 Undo.ClearUndo(graphObject);
                 DestroyImmediate(graphObject);