Fix broken 'unless' condition for Exec['set mysql password']
Fix broken 'unless' condition for Exec['set mysql password']

mysqladmin's "ping" subcommand returns 0 for both success and failure, so it is
unsuitable as a predicate. "status" had the right behavior.

Change-Id: I0f69e59b92f86dd3579b603a550aa4f91e5643fd

huit/mediawiki-vagrant,stuartbman/mediawiki-vagrant,stuartbman/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,stuartbman/mediawiki-vagrant,wikimedia/mediawiki-vagrant,HarriAlasi/wiki3dviewer,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,physikerwelt/DRMF-vagrant,physikerwelt/DRMF-vagrant,huit/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,wikimedia/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,HarriAlasi/wiki3dviewer,wikimedia/mediawiki-vagrant,stuartbman/mediawiki-vagrant,physikerwelt/DRMF-vagrant,HarriAlasi/wiki3dviewer,HarriAlasi/wiki3dviewer,stuartbman/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,HarriAlasi/wiki3dviewer,stuartbman/mediawiki-vagrant,HarriAlasi/wiki3dviewer,HarriAlasi/wiki3dviewer,huit/mediawiki-vagrant,ankita-kumari/mediawiki-vagrant,huit/mediawiki-vagrant,physikerwelt/DRMF-vagrant,ankita-kumari/mediawiki-vagrant,stuartbman/mediawiki-vagrant,huit/mediawiki-vagrant