Update mm2glab/src/api/mattermost.rs

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: braineo

mm2glab/src/api/mattermost.rs

@@ -31,7 +31,7 @@ impl MattermostClient {
         let mut headers = header::HeaderMap::new();
         headers.insert(
             header::AUTHORIZATION,
-            header::HeaderValue::from_str(&format!("Bearer {token}")).unwrap(),
+            header::HeaderValue::from_str(&format!("Bearer {token}")).expect("Invalid Mattermost token"),
         );
 
         let client = Client::builder()