Add extra guarding for group_id, remove unneeded guard in check_heater_central()

Author: bouwew

plugwise/common.py

@@ -208,7 +208,7 @@ def _get_groups(self) -> None:
                 if item.get("id") in self.gw_entities:
                     members.append(item.get("id"))
 
-            if group_type in GROUP_TYPES and members:
+            if group_type in GROUP_TYPES and members and group_id:
                 self.gw_entities[group_id] = {
                     "dev_class": group_type,
                     "model": "Group",

plugwise/util.py

@@ -84,10 +84,7 @@ def check_heater_central(xml: etree.Element) -> str:
     locator = "./appliance[type='heater_central']"
     heater_central_count = 0
     heater_central_list: list[dict[str, bool]] = []
-    if not (result := xml.findall(locator)):
-        return NONE   # pragma: no cover
-
-    for heater_central in result:
+    for heater_central in xml.findall(locator):
         if (heater_central_id := heater_central.get("id")) is None:
             continue  # pragma: no cover