make allowportrait selector available on iOS16+ only

Limelight/ViewControllers/MainFrameViewController.m

@@ -920,7 +920,6 @@ static NSMutableSet* hostList;
         // If we moved back to the center position, we should save the settings
     SettingsViewController* settingsViewController = (SettingsViewController*)[revealController rearViewController];
     settingsViewController.mainFrameViewController = self;
-    
     // enable / disable widgets acoordingly: in streamview, disable, outside of streamview, enable.
     [settingsViewController.resolutionSelector setEnabled:!self.settingsExpandedInStreamView];
     [settingsViewController.framerateSelector setEnabled:!self.settingsExpandedInStreamView];

Limelight/ViewControllers/SettingsViewController.m

@@ -393,6 +393,10 @@ BOOL isCustomResolution(CGSize res) {
     [self updateResolutionDisplayViewText];
     
     // allow portrait setting
+    bool allowPortraitSelectorEnabled;
+    if (@available(iOS 16.0, *)) allowPortraitSelectorEnabled = true; //probably need iOS 16.0 to make runtime orientation limitation woring
+    else allowPortraitSelectorEnabled = false;
+    [self.allowPortraitSelector setEnabled:allowPortraitSelectorEnabled];
     [self.allowPortraitSelector setSelectedSegmentIndex:currentSettings.allowPortrait ? 1 : 0];
     
     // lift streamview setting