Fix method invocation of send_verification_link

The signature of send_verification_link was changed in a960b57.
However, the corresponding invocation of this method in the documented public API was left unchanged, which introduced a bug reported in foo290#68.

verify_email/email_handler.py

@@ -95,7 +95,7 @@ def resend_verification_link(self, request, email, **kwargs):
 
 #  These is supposed to be called outside of this module
 def send_verification_email(request, form):
-    return _VerifyEmail().send_verification_link(request, form)
+    return _VerifyEmail().send_verification_link(request, form=form)
 
 
 #  These is supposed to be called outside of this module