Don't look for personal access tokens in the DB when the parameter/header is not passed.

app/controllers/application_controller.rb

@@ -374,7 +374,7 @@ class ApplicationController < ActionController::Base
 
   def get_user_from_personal_access_token
     token_string = params[:private_token].presence || request.headers['PRIVATE-TOKEN'].presence
-    personal_access_token = PersonalAccessToken.active.find_by_token(token_string)
+    personal_access_token = PersonalAccessToken.active.find_by_token(token_string) if token_string
     personal_access_token.user if personal_access_token
   end
 end