Incorrect DE l10n of Beta message on account home

[clasp75]

• Description of the issue:
  The German translation of the beta message contains a mistake.
  The correct imperative of “lesen” is “lies”, not “lese”, which is the subjunctive.

• Your device and browser details
  Windows 10, Firefox

• Description of steps to reproduce the issue

1. Open Firefox and set whatever is necessary to cause Memrise to respond automatically in German. (I have not seen a manual language setting, so please excuse the vagueness in this step.)
2. Log in with a valid account
3. Possibly: Activate Beta in account settings if not already set
4. Check Memrise

• Do you have any screenshots of the problem?