Don't crash for unknown MR action

src/hook.rs

@@ -40,7 +40,7 @@ pub fn format_hook(glh: &GitlabHook) -> Option<String> {
 				push.user_name,
 				push.ref_.strip_prefix("refs/tags/").unwrap_or("?!"),
 			)
-		},
+		}
 		GitlabHook::Push(push) => {
 			if push.ref_ != "refs/heads/main" {
 				// Ignore: Action not on 'main' branch
@@ -99,7 +99,13 @@ pub fn format_hook(glh: &GitlabHook) -> Option<String> {
 				Some(MergeRequestAction::Reopen) => "reopened",
 				Some(MergeRequestAction::Merge) => "merged",
 				None => return None,
-				_ => todo!(),
+				_ => {
+					log::warn!(
+						"Unsupported merge request action: {:?}",
+						merge_req.object_attributes.action
+					);
+					return None;
+				}
 			};
 			format!(
 				"[{}] {} {} merge request {}: {}{}",