This is a harmless warning which can be ignored.
The source is an outdated IPython PyLab shortcut, which will be corrected in an upcoming build of IPython. To eliminate the warning now, right-click the PyLab shortcut and click "Properties". In the "Target" field, you'll see text ending in:
...\Scripts\python.exe -c "import sys; from IPython.frontend.terminal.ipapp import launch_new_instance; sys.exit(launch_new_instance())" --pylab
Just change "IPython.frontend.terminal.ipapp" to "IPython.terminal.ipapp".
While you are at it, we suggest changing the very end of the target from "--pylab" to "--pylab=qt" so that your Pylab will run with Qt instead of the older Wx backend.