Fix: return, if CashAgentLib could not be loaded

src/ATBAPP/ATBDeviceControllerPlugin.cpp

@@ -533,6 +533,7 @@ bool ATBDeviceControllerPlugin::private_loadCashAgentLib(QString pluginName)
         qCritical() << "ATBDeviceControllerPlugin: hw is NULL";
         this->errorCode = "CashAgentLib::HW_IS_NULL";
         this->errorDescription = "ERROR: CashAgentLib object_cast is NULL: " + pluginName;
+        return false;
     }
 
     qCritical() << "ATBDeviceControllerPlugin: loaded CashAgentLib";