all players in player list can now be used for scoring games

commit 375c76b cleaned the data base structure, removing server name
and password from the player table. Since then, only player id and
name are defined per player, so there is no reason why not all of
them should be usable for scoring games

up to 375c76b, the same player name could appear more than once in the
player table: once for scoring games and once for every game server.


FIXED-IN: 4.11.1