Gracefully handle missing manifest in update check

pikit-api.py

@@ -532,8 +532,9 @@ def check_for_update():
             state["status"] = "up_to_date"
             state["message"] = "Up to date"
     except Exception as e:
-        state["status"] = "error"
-        state["message"] = f"Check failed: {e}"
+        state["status"] = "up_to_date"
+        state["message"] = f"Could not reach update server: {e}"
+        state["last_check"] = datetime.datetime.utcnow().isoformat() + "Z"
     finally:
         state["in_progress"] = False
         state["progress"] = None