Cancel long-polling for status from client side after 50 seconds.

fear_tracker/templates/game.html

@@ -362,11 +362,21 @@
 
       function checkStatus() {
         if(activeRequests.size != 0) return;
+        // From https://stackoverflow.com/a/50101022
+
+        const abort = new AbortController();
+        const signal = abort.signal;
+
+        // 50 second timeout:
+        const timeoutId = setTimeout(() => abort.abort(), 50000);
+
         fetch(new Request("{% url 'status' access_code=access_code %}"
                            + (statusObj.hash != ""
                               ? statusObj.hash + "/"
-                              : "")))
+                              : "")),
+              {signal})
           .then(response => {
+            clearTimeout(timeoutId);
             if(response.status === 304) {
               // TODO Just skip the next step?
               return statusObj;