Fix lobby gamelist issues when clients join and leave a match.
This patch will:
- Pass gameRegisterStanza to playerAssignmentsControl constructor.
- Remove handlers for onClientJoin and onClientLeave from gameRegisterStanza class.
- Call gameRegisterStanza method sendImmediately only once after all handlers have run and after updating g_PlayerAssignments .
- Remove from gameRegisterStanza the dependency on playerAssignmentsControl since the onClientJoin and onClientLeave handlers are removed.
Reviewers: Angen, wraitii
Accepted By: wraitii
Differential Revision: https://code.wildfiregames.com/D3406