Prepare Image & Video loading for E2EE

Changes the urls to make sure they are decrypted, while making sure that
it is backwards compatible to libQuotient 0.6

imports/NeoChat/Component/Timeline/VideoDelegate.qml

@@ -55,14 +55,6 @@ TimelineContainer {
 
         fillMode: VideoOutput.PreserveAspectFit
 
-        Component.onCompleted: {
-            if (downloaded) {
-                source = progressInfo.localPath
-            } else {
-                source = currentRoom.urlToMxcUrl(content.url)
-            }
-        }
-
         onDurationChanged: {
             if (!duration) {
                 vid.supportStreaming = false;