* [ios] Add protection when fontD is nil
* [ios] Add protection when fontD is nil

MrRaindrop/incubator-weex,bigconvience/weex,MrRaindrop/incubator-weex,MrRaindrop/weex,weexteam/incubator-weex,xiayun200825/weex,acton393/incubator-weex,KalicyZhou/incubator-weex,alibaba/weex,zzyhappyzzy/weex,miomin/incubator-weex,acton393/weex,dianwodaMobile/DWeex,cxfeng1/incubator-weex,MrRaindrop/weex,kfeagle/weex,dianwodaMobile/DWeex,LeeJay0226/weex,Hanks10100/weex,MrRaindrop/weex,alibaba/weex,miomin/incubator-weex,dianwodaMobile/DWeex,lvscar/weex,Hanks10100/incubator-weex,cxfeng1/weex,leoward/incubator-weex,kfeagle/weex,Hanks10100/incubator-weex,Tancy/weex,acton393/incubator-weex,xiayun200825/weex,acton393/weex,misakuo/incubator-weex,erha19/incubator-weex,xiayun200825/weex,zhangquan/weex,erha19/incubator-weex,erha19/incubator-weex,zhangquan/weex,HomHomLin/weex,zzyhappyzzy/weex,namedlock/weex,LeeJay0226/weex,leoward/incubator-weex,boboning/weex,Hanks10100/incubator-weex,miomin/incubator-weex,acton393/incubator-weex,namedlock/weex,LeeJay0226/weex,KalicyZhou/incubator-weex,acton393/incubator-weex,dianwodaMobile/DWeex,zhangquan/weex,erha19/incubator-weex,xiayun200825/weex,zzyhappyzzy/weex,erha19/incubator-weex,cxfeng1/incubator-weex,yuguitao/incubator-weex,Tancy/weex,dianwodaMobile/DWeex,MrRaindrop/incubator-weex,HomHomLin/weex,zhangquan/weex,xiayun200825/weex,weexteam/incubator-weex,Hanks10100/weex,misakuo/incubator-weex,alibaba/weex,LeeJay0226/weex,leoward/incubator-weex,leoward/incubator-weex,yuguitao/incubator-weex,Hanks10100/incubator-weex,dianwodaMobile/DWeex,Neeeo/incubator-weex,lvscar/weex,KalicyZhou/incubator-weex,KalicyZhou/incubator-weex,Tancy/weex,miomin/incubator-weex,MrRaindrop/weex,HomHomLin/weex,namedlock/weex,HomHomLin/weex,cxfeng1/weex,misakuo/incubator-weex,LeeJay0226/weex,cxfeng1/incubator-weex,miomin/incubator-weex,Hanks10100/incubator-weex,namedlock/weex,MrRaindrop/incubator-weex,Tancy/weex,cxfeng1/weex,Tancy/weex,KalicyZhou/incubator-weex,weexteam/incubator-weex,namedlock/weex,weexteam/incubator-weex,MrRaindrop/incubator-weex,acton393/weex,Hanks10100/weex,erha19/incubator-weex,miomin/incubator-weex,lvscar/weex,MrRaindrop/weex,Neeeo/incubator-weex,cxfeng1/weex,cxfeng1/incubator-weex,Neeeo/incubator-weex,weexteam/incubator-weex,erha19/incubator-weex,yuguitao/incubator-weex,boboning/weex,alibaba/weex,acton393/incubator-weex,alibaba/weex,acton393/weex,cxfeng1/incubator-weex,yuguitao/incubator-weex,misakuo/incubator-weex,Hanks10100/weex,zzyhappyzzy/weex,leoward/incubator-weex,Hanks10100/incubator-weex,bigconvience/weex,yuguitao/incubator-weex,kfeagle/weex,cxfeng1/weex,cxfeng1/weex,kfeagle/weex,KalicyZhou/incubator-weex,weexteam/incubator-weex,yuguitao/incubator-weex,miomin/incubator-weex,erha19/incubator-weex,Neeeo/incubator-weex,miomin/incubator-weex,namedlock/weex,bigconvience/weex,zzyhappyzzy/weex,misakuo/incubator-weex,Neeeo/incubator-weex,leoward/incubator-weex,boboning/weex,misakuo/incubator-weex,Neeeo/incubator-weex,kfeagle/weex,Hanks10100/weex,boboning/weex,acton393/weex,Hanks10100/incubator-weex,acton393/incubator-weex,Tancy/weex,zhangquan/weex,lvscar/weex,kfeagle/weex,MrRaindrop/incubator-weex,alibaba/weex,acton393/incubator-weex,HomHomLin/weex,bigconvience/weex,Hanks10100/incubator-weex,boboning/weex,boboning/weex,lvscar/weex,zhangquan/weex,xiayun200825/weex,bigconvience/weex,alibaba/weex,MrRaindrop/weex,HomHomLin/weex,bigconvience/weex,zzyhappyzzy/weex,lvscar/weex,LeeJay0226/weex,acton393/incubator-weex,acton393/weex,Hanks10100/weex,cxfeng1/incubator-weex