[mkgmap-dev] Commit r4506: Improve performance in combiner phase:

Version mkgmap-r4506 was committed by gerd on Thu, 28 May 2020 Improve performance in combiner phase: - Avoid to read full LBL file when we only need the header info - Avoid to repeat the extraction of the mapId field when sorting the names of the *.img files. Saves some seconds when processing many tiles. http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4506