fix which statements
fix which statements

original-commit-id: ba217de3286a43b01277d13eccce6b620363cc7c
original-commit-url: https://github.com/ipython-contrib/IPython-notebook-extensions/commit/ba217de3286a43b01277d13eccce6b620363cc7c

jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator,jcb91/jupyter_nbextensions_configurator