fix: remove incorrect endpoint cause from 401 error section

An incorrect endpoint produces timeout errors, not 401s.
Endpoint troubleshooting is already covered in the connectivity section.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: celanthe

GitLab/troubleshooting.md

@@ -12,7 +12,6 @@ This guide covers common issues and solutions when using the GitLab [Custom exec
 
 **Causes:**
 - `ORKA_TOKEN` is invalid or expired
-- `ORKA_ENDPOINT` is incorrect
 
 **Solutions:**