@anki,
I tried to quickly figure that out for you - but got nowhere :/
I am pretty sure you need to replace the MsgE6 file in /system/app (using Total Commander with root permissions).
Despite my many efforts - it failed to overwrite?
There are other ways to approach this - but since I am not bothered - I'll leave it for now
**Edit
the same problem that I encountered been reported before elsewhere:
https://www.mobileread.com/forums/sho...&postcount=330
that post/thread has a few mentions of the problem but with a possible solution
btw - friendly advice....since you seem new

the link in your last post was dead
I had to search through the posts to find which one you meant (post #80). you can hotlink to any post via the number on the post like so:
click me