[mkgmap-dev] Commit r4812: fix possible but very unlikely error in mdr25 section

Version mkgmap-r4812 was committed by gerd on Mon, 08 Nov 2021 fix possible but very unlikely error in mdr25 section - handle the case that the same combination of city name and region name occurs in two or more different countries http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4812