Core/Auth: Fix SMSG_AUTH_RESPONSE

Should send an extra byte with expansion (selecting new classes in char enum screen is now possible)

src/server/game/Server/Protocol/Handlers/AuthHandler.cpp

@@ -26,7 +26,8 @@ void WorldSession::SendAuthResponse(uint8 code, bool shortForm, uint32 queuePos)
     packet << uint32(0);                                   // BillingTimeRemaining
     packet << uint8(0);                                    // BillingPlanFlags
     packet << uint32(0);                                   // BillingTimeRested
-    packet << uint8(Expansion());                          // 0 - normal, 1 - TBC, 2 - WOTLK, must be set in database manually for each account
+    packet << uint8(Expansion());                          // 0 - normal, 1 - TBC, 2 - WOTLK, 3 - CATA; must be set in database manually for each account
+    packet << uint8(Expansion());                          // Unknown, these two show the same
 
     if (!shortForm)
     {