Bug 1161520 - Handle jobs that are missing the buildername
Bug 1161520 - Handle jobs that are missing the buildername

Since we now use the buildername as part of the error messages, we get
a KeyError if it's not present. We were already skipping over these jobs
previously, since they are also missing the branch.

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