fix after operating state Productprice

entity/Productprice_entity/afterOperatingState.js

 import("system.neon");
 import("system.vars");
 
-if(vars.get("$sys.operatingstate") != undefined 
-&& vars.get("$sys.operatingstate") != null 
-&& vars.get("$sys.operatingstate") == neon.OPERATINGSTATE_VIEW 
-&& vars.get("$local.value")) // local.value is previous operationgstate or null. This fixes not working Filter
+if(vars.exists("$sys.operatingstate") 
+    && vars.get("$sys.operatingstate") == neon.OPERATINGSTATE_VIEW 
+    && vars.get("$local.value")) // local.value is previous operationgstate or null. This fixes not working Filter
 {
     neon.refresh();
 }