[MTDJsonDemo] fix warning about supported orientations

MTDJsonDemo/Info.plist

@@ -26,5 +26,9 @@
 	</array>
 	<key>MinimumOSVersion</key>
 	<string>6.0</string>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+	</array>
 </dict>
 </plist>