[Fix] Fixed failing frontend tests due to renaming (#335)

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#335

epdb/views.py

@@ -245,7 +245,9 @@ def register(request):
             context["message"] = "Invalid username/email/password"
             return render(request, "static/login.html", context)
 
-        if UnicodeUsernameValidator(username) is not None:
+        try:
+            UnicodeUsernameValidator()(username)
+        except ValidationError:
             context["message"] = (
                 "Enter a valid username. This value may contain only letters, "
                 "numbers, and @/./+/-/_ characters."