Thumbnail offsets not returned correctly when CRLF line endings are used #1198
Description
In firmware 3.6.0 thru 3.6.2-beta.1 the offsets returned for thumbnail data by M36 are too low by 1 if the line endings are CRLF. This is because after identifying the thumbnail header line, RRF skips the CR at the end of that line but not the LF when calculating the file offset of the first line of thumbnail data. See https://forum.duet3d.com/topic/38865/incorrect-display-of-thumbnails-for-rrf.
RRF 3.5.4 works correctly in this respect. This bug was introduced when the parsing of GCode file info was speeded up for the 3.6.0 release.