Fix  a promise was created in a handler but was not returned from it, fix #318
Fix  a promise was created in a handler but was not returned from it, fix #318

akira-cn/thinkjs,Qihoo360/thinkjs,maxzhang/thinkjs,75team/thinkjs,akira-cn/thinkjs,75team/thinkjs,akira-cn/thinkjs,75team/thinkjs,thinkjs/thinkjs,snadn/thinkjs,maxzhang/thinkjs,maxzhang/thinkjs