Fix birthday field validation

flaskbb/management/forms.py

@@ -78,7 +78,7 @@ class UserForm(FlaskForm):
     password = PasswordField("Password", validators=[
         DataRequired()])
 
-    birthday = DateField(_("Birthday"), format="%d %m %Y", validators=[
+    birthday = DateField(_("Birthday"), format="%Y-%m-%d", validators=[
         Optional()])
 
     gender = StringField(_("Gender"), validators=[Optional()])

flaskbb/user/forms.py

@@ -105,7 +105,7 @@ class ChangePasswordForm(FlaskBBForm):
 
 
 class ChangeUserDetailsForm(FlaskBBForm):
-    birthday = DateField(_("Birthday"), format="%d %m %Y", validators=[Optional()])
+    birthday = DateField(_("Birthday"), format="%Y-%m-%d", validators=[Optional()])
     gender = StringField(_("Gender"), validators=[Optional()])
     location = StringField(_("Location"), validators=[Optional()])
     website = StringField(_("Website"), validators=[Optional(), URL()])