minimap: Use real line numbers for decorations instead of display ones
minimap: Use real line numbers for decorations instead of display ones

This fixes offset errors with code folding.

hlamer/kate,sandsmark/kate,hlamer/kate,DickJ/kate,hlamer/kate,hlamer/kate,hlamer/kate,hlamer/kate,hlamer/kate,hlamer/kate,sandsmark/kate,hlamer/kate,DickJ/kate,cmacq2/kate,DickJ/kate,cmacq2/kate,jfmcarreira/kate,jfmcarreira/kate,DickJ/kate,hlamer/kate,sandsmark/kate,jfmcarreira/kate,cmacq2/kate,sandsmark/kate