r7555 - Messages lost in automatic saving

[Ters]

Having unintentionally automatically loaded the save game automatically saved on exit, I noticed that all the messages were gone. I don't see why this should be different between automatic save-reload and normal save-load.

[prissi]

These messages were also lost on loading a game from commandline. That bug is there since the dawn of Simutrans (because they were cleared when the welcome message is added to the game). Fixed in -7604