Change message "Posting to Twitter.com"

[Rudolf Pietersma]

How to change the below message?
I already changed the default.po file, but the message doesn't change.

Posting to Twitter.com
We will ask you here for your Twitter username and password in order
to be able to send your micropublishing messages over to Twitter.com.
This is a bad thing! If you installed NoseRub on your own server, this
is not that bad.
Otherwise make yourself clear, that the admin of this server can see
your Twitter login credentials.
If you want to know more about why this is bad, please read this
Article by Jeremy Keith and come to our discussion group to discuss
this issue!

Rudolf.