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

src/neochatroom.cpp

@@ -311,7 +311,11 @@ QVariantMap NeoChatRoom::getUser(const QString &userID) const
 
 QUrl NeoChatRoom::urlToMxcUrl(const QUrl &mxcUrl)
 {
+#ifdef QUOTIENT_07
+    return connection()->makeMediaUrl(mxcUrl);
+#else
     return DownloadFileJob::makeRequestUrl(connection()->homeserver(), mxcUrl);
+#endif
 }
 
 QString NeoChatRoom::avatarMediaId() const