Fixing "Query string parameters prevent WA from loading"

Due to a regression, query string parameters added to the URL (like:

http://play.workadventure.localhost/_/global/maps.workadventure.localhost/starter/map.json?utm_source=sendinblue&utm_campaign=WA+-+2021+Christmap+map+launch&utm_medium=email#foo

) were causing a crash in WA.

This commit fixes the issue (and adds a E2E test)

front/src/Connexion/ConnectionManager.ts

@@ -163,12 +163,13 @@ class ConnectionManager {
                     console.error(err);
                 }
             } else {
+                const query = urlParams.toString();
                 roomPath =
                     window.location.protocol +
                     "//" +
                     window.location.host +
                     window.location.pathname +
-                    urlParams.toString() + //use urlParams because the token param must be deleted
+                    (query ? "?" + query : "") + //use urlParams because the token param must be deleted
                     window.location.hash;
             }