If multiple players are just joining, don't count them in the player count

Prevents awkward situations where only the last player of your node gets added immediately and not the others. Shouldn't affect anything otherwise?

src/p_mobj.c

@@ -10091,6 +10091,8 @@ void P_SpawnPlayer(INT32 playernum)
 			continue;
 		if (!playeringame[i] || players[i].spectator)
 			continue;
+		if (players[i].jointime <= 1) // Prevent splitscreen hosters/joiners from only adding 1 player at a time in empty servers
+			continue;
 		pcount++;
 	}