mappings/VegCSV-VegBIEN.specimens.csv: height: Removed mapping to plantobservation.overallheight, since the height is a stem field rather than a plant field. Note that a height in the organisms table will be mapped to the height in a single stemobservation for that plant, with NULL sourceaccessioncode and authorstemcode. Note also that this change is possible because no mapped datasource yet provides a valid overallheight with multiple stems or that differs from its single stem's height. (Although SALVIAS sometimes provides both a stem height and an organism height, that height is always either the same, or the organism height is invalid. See <https://projects.nceas.ucsb.edu/nceas/projects/bien/wiki/SALVIAS_issues#Some-organisms-have-one-stem-but-different-heights-in-the-organisms-and-stems-tables&gt;.)