english strings, although german website

Hi,
at the bottom of the events submission form is a checkbox saying:
“I consent to my submitted data being collected and stored as outlined by the site Datenschutzerkl?rung.”

My website is german, all strings are german, except his one.
The .po-file contains a german translation, the only place where i found that string was “events-manager/em-install.php”

Where does that string come from and more interesting, how do i change that?

kind regards
axel