[Retros] Add units: 17th update (1KA)

[Mu-Tsun Tsai]

Here's an improvement for 1KA, using almost the same idea as in my last 
problem.

Diagram:
http://www.janko.at/Retros/d.php?ff=8/PP6/PNB5/1N6/8/1P6/kPPP3P/3RR3
(13+1)

Stip: Add the missing unit(s).

Intended solution: +wKc1


Mu-Tsun