Squelch message from scm
Squelch message from scm

When I run commands like `./pants filter ...` this is the only message to stderr that comes out.  It isn't important to us and I'd like to tamp it down to debug.

Testing Done:
CI running at https://travis-ci.org/pantsbuild/pants/builds/120453837

Bugs closed: 3136

Reviewed at https://rbcommons.com/s/twitter/r/3645/

peiyuwang/pants,ity/pants,mateor/pants,15Dkatz/pants,cevaris/pants,lahosken/pants,wisechengyi/pants,ericzundel/pants,dbentley/pants,gmalmquist/pants,15Dkatz/pants,UnrememberMe/pants,benjyw/pants,peiyuwang/pants,kwlzn/pants,landism/pants,baroquebobcat/pants,manasapte/pants,fkorotkov/pants,wisechengyi/pants,foursquare/pants,baroquebobcat/pants,tdyas/pants,landism/pants,benjyw/pants,kwlzn/pants,tdyas/pants,landism/pants,kwlzn/pants,ericzundel/pants,benjyw/pants,UnrememberMe/pants,lahosken/pants,peiyuwang/pants,lahosken/pants,pantsbuild/pants,15Dkatz/pants,peiyuwang/pants,wisechengyi/pants,fkorotkov/pants,pombredanne/pants,gmalmquist/pants,benjyw/pants,foursquare/pants,mateor/pants,baroquebobcat/pants,landism/pants,pombredanne/pants,baroquebobcat/pants,tdyas/pants,manasapte/pants,wisechengyi/pants,foursquare/pants,lahosken/pants,fkorotkov/pants,ity/pants,UnrememberMe/pants,twitter/pants,foursquare/pants,fkorotkov/pants,gmalmquist/pants,dbentley/pants,cevaris/pants,twitter/pants,peiyuwang/pants,kwlzn/pants,gmalmquist/pants,mateor/pants,cevaris/pants,foursquare/pants,UnrememberMe/pants,mateor/pants,peiyuwang/pants,ity/pants,wisechengyi/pants,15Dkatz/pants,peiyuwang/pants,kwlzn/pants,gmalmquist/pants,manasapte/pants,UnrememberMe/pants,cevaris/pants,baroquebobcat/pants,benjyw/pants,jsirois/pants,wisechengyi/pants,twitter/pants,ity/pants,ericzundel/pants,dbentley/pants,ericzundel/pants,baroquebobcat/pants,benjyw/pants,manasapte/pants,ity/pants,ericzundel/pants,tdyas/pants,pantsbuild/pants,tdyas/pants,dbentley/pants,mateor/pants,cevaris/pants,wisechengyi/pants,dbentley/pants,wisechengyi/pants,lahosken/pants,ity/pants,twitter/pants,baroquebobcat/pants,pombredanne/pants,cevaris/pants,peiyuwang/pants,manasapte/pants,fkorotkov/pants,baroquebobcat/pants,mateor/pants,mateor/pants,UnrememberMe/pants,manasapte/pants,tdyas/pants,pantsbuild/pants,landism/pants,jsirois/pants,pantsbuild/pants,pantsbuild/pants,fkorotkov/pants,mateor/pants,tdyas/pants,ity/pants,15Dkatz/pants,ericzundel/pants,foursquare/pants,twitter/pants,kwlzn/pants,cevaris/pants,jsirois/pants,landism/pants,dbentley/pants,foursquare/pants,gmalmquist/pants,lahosken/pants,UnrememberMe/pants,dbentley/pants,kwlzn/pants,fkorotkov/pants,twitter/pants,landism/pants,lahosken/pants,landism/pants,gmalmquist/pants,pombredanne/pants,ericzundel/pants,twitter/pants,twitter/pants,tdyas/pants,wisechengyi/pants,baroquebobcat/pants,15Dkatz/pants,15Dkatz/pants,pombredanne/pants,UnrememberMe/pants,lahosken/pants,foursquare/pants,15Dkatz/pants,benjyw/pants,foursquare/pants,pombredanne/pants,UnrememberMe/pants,tdyas/pants,manasapte/pants,fkorotkov/pants,pombredanne/pants,pantsbuild/pants,pantsbuild/pants,twitter/pants,ericzundel/pants