If you generate a multicolor gcode file with PrusaSlicer, the purge
line gcode will look like this.
This reduces clicking sounds from the extruder, filament extrusion is reduced by 6mm.
Instead of including Configuration_prusa.h directly, include
Configuration_var which then includes the proper variant file though a
preprocessor macro.
This allows to keep the existing build system intact, but also redefine
at compile time the final header without having to make copies on the
file system.
This message is never actually shown on the LCD (it's immediately
overwritten by other content). It also include g-code in a translatable
string, which is not a good idea. It's also otherwise identical to
MSG_V2_CALIBRATION, which we should have used.
Just remove it and save some space in the process.