vikunja: adjust redirectUri back in oauth2client

basic/apps/do/vikunja-oauth-client.yaml

@@ -17,5 +17,5 @@ spec:
   scope: "openid profile email stackspin_roles"
   secretName: stackspin-vikunja-oauth-variables
   redirectUris:
-    - auth/openid/stackspin
+    - https://do.${domain}/auth/openid/stackspin
   tokenEndpointAuthMethod: client_secret_post