another small fix

app/models.py

@@ -777,8 +777,7 @@ class User(HashidMixin, UserMixin, db.Model):
     def follow_corpus(self, corpus, role=None):
         if self.is_following_corpus(corpus):
             return
-        if role is None:
-            r = CorpusFollowerRole.query.filter_by(default=True).first()
+        r = CorpusFollowerRole.query.filter_by(default=True).first() if role is None else role
         cfa = CorpusFollowerAssociation(corpus=corpus, role=r, follower=self)
         db.session.add(cfa)