Update ws.ino

Add support for humidity correction

code/espurna/ws.ino

@@ -257,6 +257,7 @@ void _wsOnStart(JsonObject& root) {
         root["webPort"] = getSetting("webPort", WEB_PORT).toInt();
         root["tmpUnits"] = getSetting("tmpUnits", SENSOR_TEMPERATURE_UNITS).toInt();
         root["tmpCorrection"] = getSetting("tmpCorrection", SENSOR_TEMPERATURE_CORRECTION).toFloat();
+        root["humCorrection"] = getSetting("humCorrection", SENSOR_HUMIDITY_CORRECTION).toFloat();
 
     }