Include traceback when plugin fails to loading (#250)

Author: j2kun

pylsp/config/config.py

@@ -32,7 +32,7 @@ def _hookexec(
         try:
             return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
         except Exception as e:  # pylint: disable=broad-except
-            log.warning(f"Failed to load hook {hook_name}: {e}")
+            log.warning(f"Failed to load hook {hook_name}: {e}", exc_info=True)
             return []