Make User.profile a single object instead of a list

Because it’s a one-to-one relationship anyway, what’s the use of lists here?

calsocial/models.py

@@ -167,7 +167,7 @@ class Profile(db.Model):  # pylint: disable=too-few-public-methods
     #: The ID of the local user this profile belongs to
     user_id = db.Column(db.Integer(), db.ForeignKey('users.id'), nullable=True, unique=True)
 
-    user = db.relationship(User, backref=db.backref('profile', lazy='dynamic'))
+    user = db.relationship(User, backref=db.backref('profile', uselist=False))
 
     #: The username this profile belongs to.  If ``None``, `user_id` must be set
     username = db.Column(db.String(length=50), nullable=True)