Update UIColor+BFKit.swift
Update UIColor+BFKit.swift

Crash on Simulator EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) fix
FabrizioBrancati/BFKit-Swift,FabrizioBrancati/BFKit-Swift,FabrizioBrancati/BFKit-Swift