Add ServerGroupChatRoomPrivate::declineSession() method.

src/chat/chat-room/server-group-chat-room-p.h

@@ -49,6 +49,7 @@ public:
 	void confirmCreation ();
 	void confirmJoining (SalCallOp *op);
 	void confirmRecreation (SalCallOp *op);
+	void declineSession (const std::shared_ptr<CallSession> &session, LinphoneReason reason);
 	void dispatchQueuedMessages ();
 
 	void subscribeReceived (LinphoneEvent *event);

src/chat/chat-room/server-group-chat-room-stub.cpp

@@ -60,6 +60,8 @@ void ServerGroupChatRoomPrivate::confirmJoining (SalCallOp *) {}
 
 void ServerGroupChatRoomPrivate::confirmRecreation (SalCallOp *) {}
 
+void ServerGroupChatRoomPrivate::declineSession (const shared_ptr<CallSession> &session, LinphoneReason reason) {}
+
 void ServerGroupChatRoomPrivate::dispatchQueuedMessages () {}
 
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