[mkgmap-dev] Commit r4169: don't print error message "Subdivision neg width" or "Subdivision neg height" for 0 values.

Version mkgmap-r4169 was committed by gerd on Fri, 20 Apr 2018 don't print error message "Subdivision neg width" or "Subdivision neg height" for 0 values. http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4169