Fixes bug #15079
When run from the command line, the engine starts up and hooks
in the mm.dat data archive. Then when the debugger console is
created, it only then iterates through all the archives for
theme files. The problem was that there was an assert in the
archive class to prevent engines using data from the wrong
subfolder in cases like the MM engine which has multiple games.
So the themes code triggered that by iterating over all the files.
When the game was run from the GUI this wasn't triggered, because
theme files had already been loaded for the launcher prior to the
game starting.
Filippos Karapetis
Paul Gilbert