Treat sg_ses '<empty>' element descriptor as no name

Some enclosures (Xyratex/NetApp shelves) leave SES element descriptor
strings blank; sg_ses prints the literal '<empty>'. Skip it so temp
sensors fall back to a generic 'Temp N' label instead of '<empty>'.

services/enclosure.py

@@ -220,7 +220,10 @@ def _parse_element_descriptors(text: str) -> dict[tuple[str, int], str]:
                 continue
             idx = int(m.group(1))
             name = m.group(2).strip()
-            if name:
+            # sg_ses prints "<empty>" when an enclosure leaves the descriptor
+            # string blank — treat that as no name so callers fall back to a
+            # generic label.
+            if name and name.lower() != "<empty>":
                 names[(etype, idx)] = name
     return names