Small fix for higher order lookup params
Small fix for higher order lookup params


Former-commit-id: ba0e42e97c8e1173d2fda1fc99c9c6efccce2bb7
clab/cnn,clab/dynet,shuheik/dynet,clab/dynet,danielhers/dynet,clab/cnn,chunyang-wen/dynet,danielhers/dynet,clab/dynet,danielhers/dynet,danielhers/dynet,clab/dynet,clab/dynet,xunzhang/dynet,shuheik/dynet,danielhers/dynet,shuheik/dynet,shuheik/dynet,clab/dynet,shuheik/dynet,danielhers/dynet,chunyang-wen/dynet,xunzhang/dynet,shuheik/dynet,clab/cnn,clab/dynet,xunzhang/dynet,danielhers/dynet,chunyang-wen/dynet,chunyang-wen/dynet,xunzhang/dynet,shuheik/dynet