vcxproj.user add QtLastBackgroundBuild cause trouble

After I updated the latest version, the QtLastBackgroundBuild field was generated in the vcxproj.user file.

My colleagues and I use the same configuration environment, and the debugging parameters of vcxproj.user hardly need to be changed.

After QtLastBackgroundBuild is added in the new version, vcxproj.user will change every time git commit is submitted. Not conducive to the user experience.