Description of problem:
  bkr job-list --whiteboard <string> cancels other limiting options

Version-Release number of selected component (if applicable):
  beaker-client-0.18.2-2.el6eng

How reproducible:
  Always

Steps to Reproduce:
  Use '--whiteboard <string>' option with other limiting option

Expected results:
  The search result should be logical AND of '--whiteboard <string>'
  and other limiting options.

Actual results:
  The search result is based on '--whiteboard <string>' limit.
  Other limiting options are ignored.

Additional information:

  If '--mine' and '--min-id' are specified, the result is logical AND of them.

    $ bkr job-list --mine --min-id 7500
    ["J:7592", "J:7591", "J:7530"]

  Among them, only J:7591 matches the conditions '--mine' AND '--min-id 7500' AND '--whiteboard 2.6.32-504'.

  However, if '--whiteboard' is added, '--mine' and '--min-id' are ignored
  and all jobs with '2.6.32-504' in whiteboard are listed.

    $ bkr job-list --mine --min-id 7500 --whiteboard '2.6.32-504'
    ["J:5697", "J:5795", "J:5817", "J:5850", "J:5851", "J:5853", "J:5854", "J:6015", "J:6048", "J:6093", "J:6097", "J:6682", "J:7017", "J:7046", "J:7047", "J:7048", "J:7049", "J:7050", "J:7101", "J:7102", "J:7103", "J:7104", "J:7105", "J:7106", "J:7107", "J:7108", "J:7109", "J:7110", "J:7121", "J:7122", "J:7123", "J:7124", "J:7125", "J:7591"]

    $ bkr job-list --whiteboard '2.6.32-504'
    ["J:5697", "J:5795", "J:5817", "J:5850", "J:5851", "J:5853", "J:5854", "J:6015", "J:6048", "J:6093", "J:6097", "J:6682", "J:7017", "J:7046", "J:7047", "J:7048", "J:7049", "J:7050", "J:7101", "J:7102", "J:7103", "J:7104", "J:7105", "J:7106", "J:7107", "J:7108", "J:7109", "J:7110", "J:7121", "J:7122", "J:7123", "J:7124", "J:7125", "J:7591"]