Apply suggestion from @burmudar

Author: burmudar

docs/api/mcp/index.mdx

@@ -57,7 +57,7 @@ If your client does not natively support specifying an OAuth 2.0 Client ID, you
 <Callout type="info">
   <ul>
     <li>Replace `your-sourcegraph-instance.com` with your Sourcegraph instance URL and `<your-client-id>` with the ID of the client you registered in the prerequisites step.</li>
-    <li>When using the `mcp-remote` fallback, ensure the OAuth client you uses has it's redirect URI set to `http://localhost:3334`.</li>
+    <li>When using the `mcp-remote` fallback, ensure the OAuth client you use has one of it's redirect URI set to `http://localhost:3334`.</li>
   </ul>
 </Callout>