account_edit_processing.php: fix warning when no games
account_edit_processing.php: fix warning when no games

When the player has joined no games, two array request variables
will not be set. In this case, set them to an empty array.

hemberger/smr,smrealms/smr,hemberger/smr,hemberger/smr,smrealms/smr,hemberger/smr,smrealms/smr