Fix BG overlay for both search controllers.

Cliqz/Search/CliqzSearchViewController.swift

@@ -85,6 +85,7 @@ class CliqzSearchViewController : UIViewController, KeyboardHelperDelegate, UIAl
 
     let searchView = Engine.sharedInstance.rootView
     fileprivate let backgroundImage = UIImageView()
+    fileprivate let privateModeOverlay = UIView.overlay(frame: CGRect.zero)
 
     private static let KVOLoading = "loading"
 
@@ -182,8 +183,11 @@ class CliqzSearchViewController : UIViewController, KeyboardHelperDelegate, UIAl
         if privateMode != self.privateMode {
             self.privateMode = privateMode
 			self.updateExtensionPreferences()
-            if privateMode {
-                self.backgroundImage.addSubview(UIView.overlay(frame: self.view.bounds))
+            if privateMode && privateModeOverlay.superview == nil {
+                backgroundImage.addSubview(privateModeOverlay)
+                privateModeOverlay.snp.makeConstraints { (make) in
+                    make.edges.equalToSuperview()
+                }
             }
         }
     }

Cliqz/Search/FirefoxSearchViewController.swift

@@ -87,9 +87,6 @@ class FirefoxSearchViewController: SiteTableViewController, KeyboardHelperDelega
 
     @objc func orientationDidChange(_ notification: Notification) {
         backgroundImage.image = BackgroundImageManager.shared.getImage()
-        if isPrivate {
-            privateModeOverlay.frame = self.view.bounds
-        }
     }
 
     override func viewDidLoad() {
@@ -111,8 +108,10 @@ class FirefoxSearchViewController: SiteTableViewController, KeyboardHelperDelega
         backgroundImage.image = BackgroundImageManager.shared.getImage()
 
         if isPrivate {
-            privateModeOverlay = UIView.overlay(frame: self.view.bounds)
             self.backgroundImage.addSubview(privateModeOverlay)
+            privateModeOverlay.snp.makeConstraints { (make) in
+                make.edges.equalToSuperview()
+            }
         }
 
         searchEngineScrollView.layer.backgroundColor = SearchViewControllerUX.SearchEngineScrollViewBackgroundColor