added validation for polling interval

custom_components/bluetti_bt/translations/de.json

@@ -4,10 +4,13 @@
       "init": {
         "data": {
           "use_controls": "Steuerung aktivieren (auf eigenes Risiko)",
-          "persistant_conn": "Dauerhafte Verbindung",
+          "persistant_conn": "Dauerhafte Verbindung (Neustart erforderlich)",
           "polling_interval": "Datenabruf-Intervall in Sekunden (Neustart erforderlich)"
         }
       }
+    },
+    "abort": {
+      "invalid_interval": "Ungültiger Datenabruf-Intervall. Verwende 5 Sekunden oder mehr"
     }
   }
 }

custom_components/bluetti_bt/translations/en.json

@@ -4,10 +4,13 @@
       "init": {
         "data": {
           "use_controls": "Use controls (use at own risk)",
-          "persistant_conn": "Persistant connection",
+          "persistant_conn": "Persistant connection (restart required)",
           "polling_interval": "Polling interval in seconds (restart required)"
         }
       }
+    },
+    "abort": {
+      "invalid_interval": "Invalid polling interval. Use 5 seconds or more"
     }
   }
 }