Description of problem:
dnf probably doesn't handle AssertionError exception when an invalid argument is passed from command line.

Version-Release number of selected component:
dnf-0:0.4.10-1.fc20.noarch

Steps to Reproduce:
dnf info -e 11
or any other command, using -e 11.

Actual results:
Traceback (most recent call last):
  File "/usr/bin/dnf", line 35, in <module>
    main.user_main(sys.argv[1:], exit_code=True)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 240, in user_main
    errcode = main(args)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 63, in main
    return _main(base, args)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 101, in _main
    cli.configure(args)
  File "/usr/lib/python2.7/site-packages/dnf/cli/cli.py", line 1315, in configure
    self.read_conf_file(opts.conffile, root, releasever, overrides)
  File "/usr/lib/python2.7/site-packages/dnf/cli/cli.py", line 1421, in read_conf_file
    self.base.logging.setup_from_dnf_conf(conf)
  File "/usr/lib/python2.7/site-packages/dnf/logging.py", line 160, in setup_from_dnf_conf
    error_level_r = _cfg_err_val2level(conf.errorlevel)
  File "/usr/lib/python2.7/site-packages/dnf/logging.py", line 80, in _cfg_err_val2level
    assert(0 <= cfg_errval <= 10)
AssertionError

Expected results:
Expected some textual error