fix(page): don't pass params to custom signout page (#1912)

* For the custom signout page addressed two issues with the query params being added to the signout url. A conditional check on the error value is now made before adding it as a query param. Also added a conditional check on the callbackUrl and if present that then gets appended as a query param to the signout api call.

* Changed fix for bug #192 to have no querystring params in the custom signout page url.

Co-authored-by: anubisoft <anubisoftprez@gmail.com>
Co-authored-by: Lluis Agusti <hi@llu.lu>

src/server/index.js

@@ -158,9 +158,8 @@ async function NextAuthHandler (req, res, userOptions) {
 
           return render.signin()
         case 'signout':
-          if (pages.signOut) {
-            return res.redirect(`${pages.signOut}${pages.signOut.includes('?') ? '&' : '?'}error=${error}`)
-          }
+          if (pages.signOut) return res.redirect(pages.signOut)
+
           return render.signout()
         case 'callback':
           if (provider) {