The player defeats herself/himself

[tos1]

When the player won a duel (not by her/his troop but by herself/himself), the player name is displayed as the defeated opponent. The ID in menus.txt is:
menu_viking_duel_win

----
The duel is over, and you have defeated {s1}. Bards will talk about your victory, and the fame of your feat will spread by word of mouth.
----

The "{s1}" in the line above seems to be mistakenly replaced by {playername}.

- How to reproduce it/when/why it happens:
It seems to be reproduced whenever the player won a duel.
Challenge a battle to any party. Select [Commander's Options]-[Call your enemy forward for a duel for honour] and fight to win if you become the challenger. If some other is selected as the challenger or no one willing to duel, you must find another party and repeat from the beginning in order to recreate the situation.

- Game version (and steam or downloaded):
AWoIaF v8.1, Warband v1.167 downloaded