Prusa MMU single feed path downgrade

Print with 4 perimeter layers minimum! This is to avoid cracking when the PTFE connector is threaded into the part.

I designed this so that I could have a backup to the multiplexer of the MMU, specifically for being able to print a single color for replacement parts if the multiplexer got jammed beyond repair. From what I understand, this is a relatively common/uncommon problem having jams in the feedpath of the multiplexer (it definitely happened to me, twice within a week or two of assembl