Remove trailing comma in configure.ac.
Remove trailing comma in configure.ac.

Summary:
- We were inadvertantly emitting a superfluous comma when generating the
configure script, causing it warn on execution. This was caused by
separating two AC_DEFINE() invocations w/ a comma.

Test Plan:
- fbconfig -r folly && fbmake runtests
- ./configure && make check on Ubuntu/FC/Mac

Reviewed By: meyering@fb.com

FB internal diff: D1008924

lifei/folly,rklabs/folly,tempbottle/folly,unmeshvrije/C--,KSreeHarsha/folly,chjp2046/folly,kernelim/folly,bobegir/folly,fw1121/folly,rklabs/folly,arg0/folly,theiver9827/folly,leolujuyi/folly,doctaweeks/folly,SeanRBurton/folly,floxard/folly,PPC64/folly,sakishum/folly,theiver9827/folly,kernelim/folly,bowlofstew/folly,Hincoin/folly,Orvid/folly,Eagle-X/folly,gaoyingie/folly,KSreeHarsha/folly,bsampath/folly,gavioto/folly,project-zerus/folly,Orvid/folly,CJstar/folly,clearlinux/folly,Hincoin/folly,fw1121/folly,zhiweicai/folly,cppfool/folly,mqeizi/folly,juniway/folly,loverszhaokai/folly,chjp2046/folly,xzmagic/folly,brunomorishita/folly,doctaweeks/folly,renyinew/folly,SeanRBurton/folly,raphaelamorim/folly,cole14/folly,reddit/folly,chjp2046/folly,sakishum/folly,bikong2/folly,shaobz/folly,cppfool/folly,romange/folly,juniway/folly,wildinto/folly,loverszhaokai/folly,Orvid/folly,unmeshvrije/C--,nickhen/folly,loverszhaokai/folly,tomhughes/folly,KSreeHarsha/folly,nickhen/folly,colemancda/folly,bikong2/folly,alexst07/folly,sakishum/folly,PoisonBOx/folly,lifei/folly,charsyam/folly,upsoft/folly,tomhughes/folly,arg0/folly,facebook/folly,bobegir/folly,cole14/folly,brunomorishita/folly,charsyam/folly,hongliangzhao/folly,romange/folly,gaoyingie/folly,mqeizi/folly,leolujuyi/folly,SeanRBurton/folly,brunomorishita/folly,leolujuyi/folly,bobegir/folly,bikong2/folly,stonegithubs/folly,floxard/folly,rklabs/folly,Hincoin/folly,clearlinux/folly,clearlylin/folly,cole14/folly,KSreeHarsha/folly,sonnyhu/folly,PPC64/folly,tempbottle/folly,loversInJapan/folly,renyinew/folly,renyinew/folly,tomhughes/folly,unmeshvrije/C--,guker/folly,reddit/folly,floxard/folly,bsampath/folly,Hincoin/folly,juniway/folly,stonegithubs/folly,constantine001/folly,romange/folly,stonegithubs/folly,lifei/folly,gaoyingie/folly,tomhughes/folly,xzmagic/folly,Orvid/folly,bowlofstew/folly,romange/folly,facebook/folly,PPC64/folly,reddit/folly,hongliangzhao/folly,doctaweeks/folly,tempbottle/folly,shaobz/folly,SammyK/folly,CJstar/folly,Eagle-X/folly,project-zerus/folly,bobegir/folly,arg0/folly,charsyam/folly,unmeshvrije/C--,upsoft/folly,colemancda/folly,constantine001/folly,Hincoin/folly,Eagle-X/folly,project-zerus/folly,raphaelamorim/folly,hongliangzhao/folly,arg0/folly,clearlylin/folly,doctaweeks/folly,unmeshvrije/C--,colemancda/folly,KSreeHarsha/folly,guker/folly,zhiweicai/folly,juniway/folly,lifei/folly,cppfool/folly,nickhen/folly,reddit/folly,SammyK/folly,juniway/folly,mqeizi/folly,zhiweicai/folly,ykarlsbrun/folly,leolujuyi/folly,facebook/folly,SeanRBurton/folly,fw1121/folly,clearlinux/folly,loverszhaokai/folly,theiver9827/folly,clearlylin/folly,sakishum/folly,tomhughes/folly,clearlinux/folly,nickhen/folly,SeanRBurton/folly,gavioto/folly,zhiweicai/folly,clearlylin/folly,bobegir/folly,kernelim/folly,shaobz/folly,raphaelamorim/folly,raphaelamorim/folly,rklabs/folly,bsampath/folly,wildinto/folly,hongliangzhao/folly,loverszhaokai/folly,alexst07/folly,ykarlsbrun/folly,xzmagic/folly,guker/folly,gavioto/folly,reddit/folly,colemancda/folly,romange/folly,wildinto/folly,renyinew/folly,cppfool/folly,SammyK/folly,yangjin-unique/folly,nickhen/folly,lifei/folly,floxard/folly,renyinew/folly,mqeizi/folly,upsoft/folly,stonegithubs/folly,PPC64/folly,bowlofstew/folly,rklabs/folly,zhiweicai/folly,PoisonBOx/folly,Orvid/folly,PoisonBOx/folly,raphaelamorim/folly,Eagle-X/folly,brunomorishita/folly,fw1121/folly,yangjin-unique/folly,clearlylin/folly,yangjin-unique/folly,yangjin-unique/folly,xzmagic/folly,sonnyhu/folly,cole14/folly,facebook/folly,guker/folly,gaoyingie/folly,chjp2046/folly,colemancda/folly,PPC64/folly,loversInJapan/folly,stonegithubs/folly,tempbottle/folly,sonnyhu/folly,CJstar/folly,CJstar/folly,project-zerus/folly,shaobz/folly,cppfool/folly,PoisonBOx/folly,ykarlsbrun/folly,bowlofstew/folly,bowlofstew/folly,gavioto/folly,mqeizi/folly,brunomorishita/folly,arg0/folly,cole14/folly,bsampath/folly,leolujuyi/folly,upsoft/folly,upsoft/folly,project-zerus/folly,sakishum/folly,clearlinux/folly,wildinto/folly,charsyam/folly,alexst07/folly,alexst07/folly,floxard/folly,sonnyhu/folly,sonnyhu/folly,tempbottle/folly,loversInJapan/folly,shaobz/folly,theiver9827/folly,constantine001/folly,bikong2/folly,kernelim/folly,xzmagic/folly,wildinto/folly,doctaweeks/folly,loversInJapan/folly,CJstar/folly,loversInJapan/folly,theiver9827/folly,chjp2046/folly,ykarlsbrun/folly,constantine001/folly,hongliangzhao/folly,gaoyingie/folly,Eagle-X/folly,SammyK/folly,PoisonBOx/folly,constantine001/folly,gavioto/folly,yangjin-unique/folly,bikong2/folly,guker/folly,SammyK/folly,fw1121/folly,ykarlsbrun/folly,kernelim/folly,alexst07/folly,unmeshvrije/C--,facebook/folly,bsampath/folly