Modular integrations Manager: Improve dark theme management

Riot/ViewController/Widgets/IntegrationManagerViewController.m

@@ -36,9 +36,6 @@ NSString *const kJavascriptSendResponseToModular = @"riotIOS.sendResponse('%@',
     NSString *scalarToken;
 
     MXHTTPOperation *operation;
-
-    // Observe kRiotDesignValuesDidChangeThemeNotification to handle user interface theme change.
-    id kRiotDesignValuesDidChangeThemeNotificationObserver;
 }
 
 @end
@@ -64,12 +61,6 @@ NSString *const kJavascriptSendResponseToModular = @"riotIOS.sendResponse('%@',
 
     [operation cancel];
     operation = nil;
-
-    if (kRiotDesignValuesDidChangeThemeNotificationObserver)
-    {
-        [[NSNotificationCenter defaultCenter] removeObserver:kRiotDesignValuesDidChangeThemeNotificationObserver];
-        kRiotDesignValuesDidChangeThemeNotificationObserver = nil;
-    }
 }
 
 - (void)viewDidLoad
@@ -79,24 +70,10 @@ NSString *const kJavascriptSendResponseToModular = @"riotIOS.sendResponse('%@',
     webView.scalesPageToFit = NO;
     webView.scrollView.bounces = NO;
 
-    webView.delegate = self;
-
-    // Observe user interface theme change.
-    kRiotDesignValuesDidChangeThemeNotificationObserver = [[NSNotificationCenter defaultCenter] addObserverForName:kRiotDesignValuesDidChangeThemeNotification object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *notif) {
-
-        [self userInterfaceThemeDidChange];
-
-    }];
-    [self userInterfaceThemeDidChange];
-}
-
-- (void)userInterfaceThemeDidChange
-{
-    self.view.backgroundColor = kRiotPrimaryBgColor;
-    webView.backgroundColor = kRiotPrimaryBgColor;
+    // Disable opacity so that the webview background uses the current interface theme
     webView.opaque = NO;
-    
-    self.activityIndicator.backgroundColor = kRiotOverlayColor;
+
+    webView.delegate = self;
 }
 
 - (void)viewWillAppear:(BOOL)animated