warn user when location permission is denied

app/templates/player_base.html

@@ -36,6 +36,7 @@ function showError(error) {
     switch(error.code) {
         case error.PERMISSION_DENIED:
             console.log("User denied the request for Geolocation.")
+            alert("Please refresh page and allow location sharing, otherwise the game won't work :'(")
             break;
         case error.POSITION_UNAVAILABLE:
             console.log("Location information is unavailable.")