use more meaningful icon for 'All Media'

deltachat-ios/Assets.xcassets/rectangle.on.rectangle.imageset/Contents.json → deltachat-ios/Assets.xcassets/photo.on.rectangle.imageset/Contents.json

@@ -2,17 +2,17 @@
   "images" : [
     {
       "idiom" : "universal",
-      "filename" : "rectangle.on.rectangle.png",
+      "filename" : "photo.on.rectangle.png",
       "scale" : "1x"
     },
     {
       "idiom" : "universal",
-      "filename" : "rectangle.on.rectangle@2x.png",
+      "filename" : "photo.on.rectangle@2x.png",
       "scale" : "2x"
     },
     {
       "idiom" : "universal",
-      "filename" : "rectangle.on.rectangle@3x.png",
+      "filename" : "photo.on.rectangle@3x.png",
       "scale" : "3x"
     }
   ],

deltachat-ios/Coordinator/AppCoordinator.swift

@@ -50,7 +50,7 @@ class AppCoordinator {
     private func createAllMediaNavigationController() -> UINavigationController {
         let root = AllMediaViewController(dcAccounts: dcAccounts)
         let nav = UINavigationController(rootViewController: root)
-        let settingsImage = UIImage(named: "rectangle.on.rectangle")
+        let settingsImage = UIImage(named: "photo.on.rectangle")
         nav.tabBarItem = UITabBarItem(title: String.localized("menu_all_media"), image: settingsImage, tag: chatsTab)
         return nav
     }