Originally Posted by Torchy McFlux

Frankly, there's no way a crankarm should be that close to a chainstay on a properly designed and built frame. If your measurement is correct and the mid ring is a whole 45mm from the center of the seattube, then the bad design of the frame is to blame.
You can either sacrifice ideal chainline and front derailleur performance by putting a slightly longer bottom bracket spindle in, or return the frame to the manufacturer and demand a refund on a poorly designed product that you unnecessarily have to make compromises for to use.