Fixed callback URL in .env.example

Author: aaguiarz

01-Login/.env.example

@@ -1,5 +1,5 @@
 AUTH0_CLIENT_ID={CLIENT_ID}
 AUTH0_DOMAIN={DOMAIN}
 AUTH0_CLIENT_SECRET={CLIENT_SECRET}
-AUTH0_CALLBACK_URL={CALLBACK_URL}
+AUTH0_CALLBACK_URL=
 API_ID={API_AUDIENCE}