Don't require current_password for settings if user doesn't have one

app/controllers/auth_users_controller.rb

@@ -24,7 +24,13 @@ class AuthUsersController < ApplicationController
 	def update
 		@auth_user = load_auth_user
 
-		if @auth_user.update_with_password(auth_user_params)
+		# If the user has a password, then the `current_password` field is required
+		# when updating. If not, then it's not!
+		success = @auth_user.uses_password? ?
+			@auth_user.update_with_password(auth_user_params) :
+			@auth_user.update(auth_user_params)
+
+		if success
 			# NOTE: Changing the password will sign you out, so make sure we stay
 			# signed in!
 			bypass_sign_in @auth_user, scope: :auth_user

app/views/auth_users/edit.html.erb

@@ -38,6 +38,8 @@
     </div>
   </fieldset>
 
+  <%# Current password is only required if you have one! %>
+  <% if @auth_user.uses_password? %>
     <fieldset>
       <div class="field">
         <%= f.label :current_password %>
@@ -46,6 +48,7 @@
         <%= f.password_field :current_password, autocomplete: "current-password" %>
       </div>
     </fieldset>
+  <% end %>
 
   <div class="actions">
     <%= f.submit "Save changes" %>