MXImageView: use the new interface [setImageURI:...] instead of the deprecated one [setImageURL:...] .

Note - DirectoryServerTableViewCell:
Presently the thirdPartyProtocolInstance.icon is not a Matrix Content URI. We could not use here MXKImageView setImageURI method
 without breaking the instance icon rendering. We use the deprecated interface until this point is fixed on the server side.

Riot/Modules/Room/Views/Title/Preview/PreviewRoomTitleView.m

@@ -1,6 +1,7 @@
 /*
  Copyright 2016 OpenMarket Ltd
  Copyright 2017 Vector Creations Ltd
+ Copyright 2018 New Vector Ltd
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -96,7 +97,13 @@
     {
         if (self.roomAvatarURL)
         {
-            [self.roomAvatar setImageURL:self.roomAvatarURL withType:nil andImageOrientation:UIImageOrientationUp previewImage:[UIImage imageNamed:@"placeholder"]];
+            [self.roomAvatar setImageURI:self.roomAvatarURL
+                                withType:nil
+                     andImageOrientation:UIImageOrientationUp
+                           toFitViewSize:self.roomAvatar.frame.size
+                              withMethod:MXThumbnailingMethodCrop
+                            previewImage:[UIImage imageNamed:@"placeholder"]
+                            mediaManager:self.mxRoom.mxSession.mediaManager];
         }
         else
         {