Fixed Valgrind warnings

Running cockatrice in valgrind i didn't found any bad memory leak
(good!), but only a few jumps depending on uninitialized variables.
Even if the possibility of crashes are remote, it's nice to sort them
out.

cockatrice/src/gamesmodel.cpp

@@ -93,6 +93,7 @@ GamesProxyModel::GamesProxyModel(QObject *parent, ServerInfo_User *_ownUser)
     : QSortFilterProxyModel(parent),
           ownUser(_ownUser),
           unavailableGamesVisible(false),
+          passwordProtectedGamesVisible(false),
           maxPlayersFilterMin(-1),
           maxPlayersFilterMax(-1)
 {