When a user moves, do not trigger group creation

In order to avoid triggering group creation when walking next to someone we should avoid creating a group unless the user stops next to the other members of the group.

back/src/Model/GameRoom.ts

@@ -138,6 +138,12 @@ export class GameRoom {
         if (user.group === undefined) {
             // If the user is not part of a group:
             //  should he join a group?
+
+            // If the user is moving, don't try to join
+            if (user.getPosition().moving) {
+                return;
+            }
+
             const closestItem: User|Group|null = this.searchClosestAvailableUserOrGroup(user);
 
             if (closestItem !== null) {