Fix incorrect default for missing "offline" property data (#271)

* Fix incorrect default for missing "offline" property data

* Trigger Build

Author: bachya

simplipy/system/v3.py

@@ -254,7 +254,7 @@ def light(self) -> bool:
         )
 
     @property  # type: ignore
-    @guard_from_missing_data(True)
+    @guard_from_missing_data(False)
     def offline(self) -> bool:
         """Return whether the system is offline.
 

tests/system/test_v3.py

@@ -289,7 +289,7 @@ async def test_missing_property(caplog, v3_server, v3_subscriptions_response):
 
         await system.update(include_settings=False, include_entities=False)
 
-        assert system.offline is True
+        assert system.offline is False
         assert any(
             "SimpliSafe didn't return data for property: offline" in e.message
             for e in caplog.records