command/rsync-auto: properly exit on interrupt
command/rsync-auto: properly exit on interrupt

Currently, interrupting 'vagrant rsync-auto' once it's waiting for
filesystem events has no effect. Appears to be a deadlock related to
signal handlers in Ruby 2.0 [0].

Remove call to `thread.join` in signal handler. The handler doesn't
need to wait for `true` to be added to the queue; it just needs to
launch the thread.

[0]: https://bugs.ruby-lang.org/issues/7917

sideci-sample/sideci-sample-vagrant,benh57/vagrant,gpkfr/vagrant,philwrenn/vagrant,myrjola/vagrant,wangfakang/vagrant,Chhunlong/vagrant,carlosefr/vagrant,lukebakken/vagrant,blueyed/vagrant,benizi/vagrant,chrisroberts/vagrant,jtopper/vagrant,sax/vagrant,jmanero/vagrant,invernizzi-at-google/vagrant,MiLk/vagrant,janek-warchol/vagrant,jberends/vagrant,PatOShea/vagrant,chrisroberts/vagrant,dhoer/vagrant,jhoblitt/vagrant,ArloL/vagrant,taliesins/vagrant,theist/vagrant,lonniev/vagrant,tbriggs-curse/vagrant,gbarberi/vagrant,fnewberg/vagrant,lukebakken/vagrant,jkburges/vagrant,carlosefr/vagrant,dharmab/vagrant,h4ck3rm1k3/vagrant,wkolean/vagrant,ArloL/vagrant,invernizzi-at-google/vagrant,mpoeter/vagrant,benizi/vagrant,signed8bit/vagrant,bshurts/vagrant,loren-osborn/vagrant,cgvarela/vagrant,lukebakken/vagrant,modulexcite/vagrant,BlakeMesdag/vagrant,teotihuacanada/vagrant,shtouff/vagrant,tschortsch/vagrant,benizi/vagrant,bheuvel/vagrant,patrys/vagrant,cgvarela/vagrant,philoserf/vagrant,marxarelli/vagrant,aneeshusa/vagrant,kamazee/vagrant,loren-osborn/vagrant,PatOShea/vagrant,cgvarela/vagrant,vamegh/vagrant,jean/vagrant,philoserf/vagrant,legal90/vagrant,muhanadra/vagrant,jkburges/vagrant,jhoblitt/vagrant,aaam/vagrant,patrys/vagrant,gpkfr/vagrant,TheBigBear/vagrant,teotihuacanada/vagrant,legal90/vagrant,crashlytics/vagrant,dustymabe/vagrant,rivy/vagrant,dharmab/vagrant,jfchevrette/vagrant,kamigerami/vagrant,theist/vagrant,Endika/vagrant,tschortsch/vagrant,taliesins/vagrant,h4ck3rm1k3/vagrant,aaam/vagrant,sax/vagrant,modulexcite/vagrant,invernizzi-at-google/vagrant,kamazee/vagrant,philoserf/vagrant,tknerr/vagrant,philwrenn/vagrant,janek-warchol/vagrant,signed8bit/vagrant,mkuzmin/vagrant,Chhunlong/vagrant,Avira/vagrant,senglin/vagrant,sni/vagrant,bdwyertech/vagrant,apertoso/vagrant,bryson/vagrant,modulexcite/vagrant,sax/vagrant,clinstid/vagrant,Sgoettschkes/vagrant,fnewberg/vagrant,tschortsch/vagrant,benh57/vagrant,evverx/vagrant,loren-osborn/vagrant,tbarrongh/vagrant,dustymabe/vagrant,justincampbell/vagrant,stephancom/vagrant,zsjohny/vagrant,tjanez/vagrant,PatrickLang/vagrant,obnoxxx/vagrant,benizi/vagrant,stephancom/vagrant,fnewberg/vagrant,justincampbell/vagrant,jean/vagrant,janek-warchol/vagrant,Endika/vagrant,ferventcoder/vagrant,bheuvel/vagrant,Chhunlong/vagrant,ianmiell/vagrant,patrys/vagrant,rivy/vagrant,mitchellh/vagrant,pwnall/vagrant,mpoeter/vagrant,iNecas/vagrant,dhoer/vagrant,lonniev/vagrant,sax/vagrant,mwarren/vagrant,jberends/vagrant,denisbr/vagrant,tomfanning/vagrant,wkolean/vagrant,jtopper/vagrant,rivy/vagrant,jberends/vagrant,petems/vagrant,otagi/vagrant,tknerr/vagrant,senglin/vagrant,MiLk/vagrant,gitebra/vagrant,aaam/vagrant,gpkfr/vagrant,tjanez/vagrant,tjanez/vagrant,Sgoettschkes/vagrant,kamazee/vagrant,benh57/vagrant,senglin/vagrant,TheBigBear/vagrant,ArloL/vagrant,legal90/vagrant,wangfakang/vagrant,mkuzmin/vagrant,mitchellh/vagrant,jfchevrette/vagrant,apertoso/vagrant,otagi/vagrant,taliesins/vagrant,kalabiyau/vagrant,carlosefr/vagrant,zsjohny/vagrant,bheuvel/vagrant,aneeshusa/vagrant,teotihuacanada/vagrant,gbarberi/vagrant,apertoso/vagrant,petems/vagrant,philwrenn/vagrant,mwarren/vagrant,tbarrongh/vagrant,Sgoettschkes/vagrant,lonniev/vagrant,Avira/vagrant,jkburges/vagrant,doy/vagrant,tomfanning/vagrant,gajdaw/vagrant,jmanero/vagrant,Chhed13/vagrant,obnoxxx/vagrant,fnewberg/vagrant,darkn3rd/vagrant,tomfanning/vagrant,zsjohny/vagrant,sni/vagrant,TheBigBear/vagrant,nickryand/vagrant,Chhed13/vagrant,blueyed/vagrant,ferventcoder/vagrant,iNecas/vagrant,mwarren/vagrant,shtouff/vagrant,Chhunlong/vagrant,johntron/vagrant,PatOShea/vagrant,tomfanning/vagrant,kamigerami/vagrant,mpoeter/vagrant,genome21/vagrant,mwrock/vagrant,tbarrongh/vagrant,gajdaw/vagrant,signed8bit/vagrant,modulexcite/vagrant,PatrickLang/vagrant,PatrickLang/vagrant,jkburges/vagrant,kamigerami/vagrant,tbriggs-curse/vagrant,theist/vagrant,vamegh/vagrant,marxarelli/vagrant,gbarberi/vagrant,myrjola/vagrant,bheuvel/vagrant,teotihuacanada/vagrant,ianmiell/vagrant,bshurts/vagrant,ianmiell/vagrant,gbarberi/vagrant,krig/vagrant,wangfakang/vagrant,dharmab/vagrant,mkuzmin/vagrant,jean/vagrant,aneeshusa/vagrant,crashlytics/vagrant,Endika/vagrant,TheBigBear/vagrant,crashlytics/vagrant,jtopper/vagrant,muhanadra/vagrant,philwrenn/vagrant,channui/vagrant,pwnall/vagrant,chrisroberts/vagrant,bshurts/vagrant,h4ck3rm1k3/vagrant,miguel250/vagrant,blueyed/vagrant,rivy/vagrant,juiceinc/vagrant,stephancom/vagrant,sideci-sample/sideci-sample-vagrant,PatOShea/vagrant,muhanadra/vagrant,iNecas/vagrant,jfchevrette/vagrant,mitchellh/vagrant,miguel250/vagrant,Chhed13/vagrant,Sgoettschkes/vagrant,pwnall/vagrant,dustymabe/vagrant,sni/vagrant,chrisvire/vagrant,senglin/vagrant,johntron/vagrant,channui/vagrant,doy/vagrant,aneeshusa/vagrant,marxarelli/vagrant,juiceinc/vagrant,doy/vagrant,miguel250/vagrant,evverx/vagrant,nickryand/vagrant,stephancom/vagrant,wkolean/vagrant,zsjohny/vagrant,dhoer/vagrant,darkn3rd/vagrant,genome21/vagrant,channui/vagrant,petems/vagrant,wkolean/vagrant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