Use of PC15 instead of PC14

[daschu117]

Why not use PC14 that's part of the z-probe header for the microswitch? I suppose that I can see it being simpler to make independent JST headers instead of awkwardly merging two cables into one header or encouraging the use of non-polarized dupont plugs for the servo connection.

But it should be equivalent and tidier, right? Especially if someone was interested in a filament runout sensor and this mod.

Anyway, thanks for making this available!