Fix randomly assign problem in breakout rooms

The problem was caused because of PureComponent shallow
comparison, the users list in state are not changing his
reference

close #7905

bigbluebutton-html5/imports/ui/components/actions-bar/create-breakout-room/component.jsx

@@ -353,9 +353,13 @@ class BreakoutRoom extends PureComponent {
     const { users } = this.state;
 
     const idxUser = users.findIndex(user => user.userId === userId);
-    users[idxUser].room = room;
+
+    const usersCopy = [...users];
+
+    usersCopy[idxUser].room = room;
+
     this.setState({
-      users,
+      users: usersCopy,
       valid: this.getUserByRoom(0).length !== users.length,
     });
   }