added missing __unit cache

plugins/modules/system_service.py

@@ -43,6 +43,7 @@ class Module(SystemdUnitModule):
 
     def prepare(self):
         self.unitfile = (SYSTEMD_SERVICE_CONFIG / self.get("name")).with_stem(".service")
+        self.__unit = None
         if self.get("type", "simple") != "oneshot" and len(self.get("start")) > 1:
             self.module.fail_json("only oneshot services are allowed to have multiple start commands", **self.result)
 

plugins/modules/target.py

@@ -25,6 +25,7 @@ class Module(SystemdUnitModule):
 
     def prepare(self):
         self.unitfile = (SYSTEMD_SERVICE_CONFIG/ self.get("name")).with_stem(".target")
+        self.__unit = None
 
     def header(self) -> str:
         section = super().header()