[CLIENT] can't invite in custom made game when 5 in lobby

Here is how to reproduce that bug :

• create a custom game : play > create custom [choose whatever mode, we tested them]
• invite 4 persons
• have them all join the lobby Observe : as soon as you are five in the lobby you can not invite new persons anymore

If one hovers above the greyed-out "invite" button, the message "lobby is full" appears (even though it's not case)

If more than 4 persons are invited in the first place, they can all accept (up to the limit of positions for the type of game)

Thanks a lot ~ Lyu