reduce title bar font size

deltachat-ios/Controller/ChatListController.swift

@@ -21,7 +21,7 @@ class ChatListController: UITableViewController {
         let navTapGesture = UITapGestureRecognizer(target: self, action: #selector(onNavigationTitleTapped))
         view.addGestureRecognizer(navTapGesture)
         view.isUserInteractionEnabled = true
-        view.font = UIFont.systemFont(ofSize: 20, weight: .semibold)
+        view.font = UIFont.systemFont(ofSize: 18, weight: .semibold)
         return view
     }()
 

deltachat-ios/Coordinator/AppCoordinator.swift

@@ -129,7 +129,7 @@ class AppCoordinator {
         } else {
             presentWelcomeController()
         }
-        UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 20, weight: .semibold)]
+        UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 18, weight: .semibold)]
     }
 
     func presentWelcomeController() {