Warn user that installing KhiCAS will remove Epsilon

[viciscat]

Hello small sugestion:
Warn the user that if they install KhiCAS, epsilon in slot B will be removed. I wasn't aware of this and that was a problem since I wanted to keep E18. I had to reinstall E18.2.0 and do the whole Phi procedure again. So yea a basic warning will do the trick.