folly::dynamic: comment about std::vector const-iter erase issue
folly::dynamic: comment about std::vector const-iter erase issue

Test Plan: none

Reviewed By: delong.j@fb.com

FB internal diff: D543196


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