Description of problem: Trying to mock shell on RHEL5x32 fails because of wrong parameter order given to usermod

Version-Release number of selected component (if applicable): mock-1.4.8-1.fc27.noarch


How reproducible: try to mock shell to RHEL5x32 distribution with mock-1.4.8-1.fc27.noarch


Steps to Reproduce:
1. mock -r 2015r4-el5-occonnectors-candidate-27669-19963 shell -v
2.
3.

Actual results: Fails to start the shell with error "Command failed". Verbose output provided below.


Expected results: Start shell


Additional info:
Works fine with mock-1.4.6-1.fc27.noarch

However with mock-1.4.8-1.fc27.noarch it fails:
...
DEBUG: configure yum priorities
DEBUG: configure yum rhnplugin
DEBUG: child environment: None
DEBUG: Executing command: ['/usr/bin/systemd-nspawn', '-q', '-M', 'a467b800cf544171a6be540b074027c2', '-D', '/aux1/mock/2015r4-el5-occonnectors-candidate-27669-19963/root', '-a', '--setenv=TERM=vt100', '--setenv=SHELL=/bin/bash', '--setenv=HOME=/builddir', '--setenv=HOSTNAME=mock', '--setenv=PATH=/usr/bin:/bin:/usr/sbin:/sbin', '--setenv=PROMPT_COMMAND=printf "\\033]0;<mock-chroot>\\007"', '--setenv=PS1=<mock-chroot> \\s-\\v\\$ ', '--setenv=LANG=en_US.UTF-8', '/usr/sbin/usermod', '--non-unique', '-u', '1000', 'mockbuild'] with env {'TERM': 'vt100', 'SHELL': '/bin/bash', 'HOME': '/builddir', 'HOSTNAME': 'mock', 'PATH': '/usr/bin:/bin:/usr/sbin:/sbin', 'PROMPT_COMMAND': 'printf "\\033]0;<mock-chroot>\\007"', 'PS1': '<mock-chroot> \\s-\\v\\$ ', 'LANG': 'en_US.UTF-8'} and shell False
DEBUG: DEBUG: Unsharing. Flags: 134217728
DEBUG: Usage: usermod [options] LOGIN
DEBUG: Options:
DEBUG:   -a, --append			append the user to the supplemental GROUPS
...