Remove '--format=ustar' test to avoid error if uid is too important.

Because of (as in https://developer.windriver.com/thread/1154):

eval tar --format=ustar -chf - build
tar: value 43493816 out of uid_t range 0..2097151
tar: Exiting with failure status due to previous errors
Make sure to stay in 1.x for nxlog.