fix rnnlm example
fix rnnlm example

mrzu/cnn,zhangscth/cnn,clab/cnn,shuheik/dynet,chunyang-wen/dynet,danielhers/dynet,danielhers/dynet,xunzhang/dynet,shuheik/dynet,shuheik/dynet,clab/dynet,danielhers/dynet,danielhers/dynet,clab/dynet,shuheik/dynet,Abasyoni/dynet,yoavg/cnn,cherryc/dynet,shuheik/dynet,danielhers/dynet,kaishengyao/cnn,kamigaito/cnn,Peilun-Li/dynet,cherryc/dynet,chunyang-wen/dynet,echohenry2006/cnn,mitchellstern/dynet,clab/dynet,kamigaito/cnn,mitchellstern/dynet,Peilun-Li/dynet,Peilun-Li/dynet,yanweifu/cnn,clab/dynet,shuheik/dynet,Aureliu/cnn,clab/dynet,dhgarrette/cnn,dhgarrette/cnn,xunzhang/dynet,clab/cnn,chunyang-wen/dynet,Abasyoni/dynet,xunzhang/dynet,cherryc/dynet,chunyang-wen/dynet,clab/dynet,kaishengyao/cnn,xunzhang/dynet,danielhers/dynet,clab/cnn,danielhers/dynet,clab/dynet,ndnlp/cnn,dhgarrette/cnn,yoavg/cnn,Abasyoni/dynet,shuheik/dynet