✏️ Fix typo in self-hosting troubleshooting (#1478)

Hi Arno,

Thank you for your amazing project.

I have made the following small change in the docs:
- "signed" text should be "sign", fixed this small oversight in the
docs.

apps/docs/self-hosting/troubleshoot.mdx

@@ -5,7 +5,7 @@ icon: bug
 
 ## My workspace is showing Free plan and 200 chats limit
 
-You most likely forgot to set up an `ADMIN_EMAIL` variable or did not signed up using the specified email. You can also set the `DEFAULT_WORKSPACE_PLAN` variable to the value of your choice (`FREE`, `STARTER`, `PRO`, `LIFETIME`, `UNLIMITED`) to attribute the specified plan to all newly created workspaces. You can also directly connect to your database and update the `Workspace` table to change the plan of an existing workspace.
+You most likely forgot to set up an `ADMIN_EMAIL` variable or did not sign up using the specified email. You can also set the `DEFAULT_WORKSPACE_PLAN` variable to the value of your choice (`FREE`, `STARTER`, `PRO`, `LIFETIME`, `UNLIMITED`) to attribute the specified plan to all newly created workspaces. Otherwise, you can also directly connect to your database and update the `Workspace` table to change the plan of an existing workspace.
 
 ## I can't upload files