fix ev in chargepoint_data.py

Author: benderl

packages/control/chargepoint/chargepoint_data.py

@@ -150,7 +150,7 @@ class Set:
 @dataclass
 class Config:
     configuration: Dict = field(default_factory=empty_dict_factory)
-    ev: int = 0
+    _ev: int = 0
     name: str = "neuer Ladepunkt"
     type: Optional[str] = None
     template: int = 0