Bug 1155321 - fix filter params for jobs not in a group
Bug 1155321 - fix filter params for jobs not in a group

If a job (like a build) is not in a group, then the job details string
for filtering by fields showed “unknown ?” as the job-group name and
symbol.  Those are legitimate values internally, but the user shouldn’t
see them.

KWierso/treeherder,kapy2010/treeherder,wlach/treeherder,vaishalitekale/treeherder,adusca/treeherder,deathping1994/treeherder,avih/treeherder,rail/treeherder,tojonmz/treeherder,wlach/treeherder,sylvestre/treeherder,moijes12/treeherder,edmorley/treeherder,deathping1994/treeherder,tojon/treeherder,kapy2010/treeherder,avih/treeherder,deathping1994/treeherder,KWierso/treeherder,jgraham/treeherder,glenn124f/treeherder,vaishalitekale/treeherder,tojonmz/treeherder,sylvestre/treeherder,wlach/treeherder,moijes12/treeherder,kapy2010/treeherder,akhileshpillai/treeherder,deathping1994/treeherder,parkouss/treeherder,akhileshpillai/treeherder,adusca/treeherder,sylvestre/treeherder,kapy2010/treeherder,wlach/treeherder,adusca/treeherder,rail/treeherder,tojonmz/treeherder,vaishalitekale/treeherder,glenn124f/treeherder,tojon/treeherder,wlach/treeherder,rail/treeherder,sylvestre/treeherder,deathping1994/treeherder,akhileshpillai/treeherder,gbrmachado/treeherder,moijes12/treeherder,vaishalitekale/treeherder,moijes12/treeherder,glenn124f/treeherder,glenn124f/treeherder,gbrmachado/treeherder,tojonmz/treeherder,vaishalitekale/treeherder,glenn124f/treeherder,avih/treeherder,parkouss/treeherder,parkouss/treeherder,akhileshpillai/treeherder,KWierso/treeherder,KWierso/treeherder,avih/treeherder,parkouss/treeherder,moijes12/treeherder,glenn124f/treeherder,gbrmachado/treeherder,tojon/treeherder,jgraham/treeherder,adusca/treeherder,gbrmachado/treeherder,tojonmz/treeherder,tojonmz/treeherder,gbrmachado/treeherder,wlach/treeherder,deathping1994/treeherder,tojon/treeherder,jgraham/treeherder,jgraham/treeherder,edmorley/treeherder,parkouss/treeherder,adusca/treeherder,vaishalitekale/treeherder,avih/treeherder,gbrmachado/treeherder,adusca/treeherder,edmorley/treeherder,jgraham/treeherder,parkouss/treeherder,rail/treeherder,rail/treeherder,kapy2010/treeherder,sylvestre/treeherder,edmorley/treeherder,moijes12/treeherder,jgraham/treeherder,sylvestre/treeherder,akhileshpillai/treeherder,rail/treeherder,akhileshpillai/treeherder,avih/treeherder