Updating of warning message when we try to close screen sharing

Trying to close screen sharing is alway process when a peer connection is closed.

Signed-off-by: Gregoire Parant <g.parant@thecodingmachine.com>

front/src/WebRtc/SimplePeer.ts

@@ -259,7 +259,7 @@ export class SimplePeer {
                 console.warn(
                     "closeScreenSharingConnection => Tried to close connection for user " +
                         userId +
-                        " but could not find user"
+                        " but could not find user or no peer connection started"
                 );
                 return;
             }