Hi Andrzej,
i don't think so. Besides, i recommend to avoid the built-in Jetty Server. Instead, download the server version of Jetty or Tomcat and add it in your eclipse. Have a look at the following blog post for more information: How to install a basic development environment for SAPUI5
Other users solved similar problems on the same way. See SAPUI5 web app preview locked files
Regards
Michael