rename `trackMod` -> `desiredTracks` in this stopgap race condition-squashing hack
rename `trackMod` -> `desiredTracks` in this stopgap race condition-squashing hack

nathandunn/jbrowse,nathandunn/jbrowse,nathandunn/jbrowse,GMOD/jbrowse,GMOD/jbrowse,GMOD/jbrowse,nathandunn/jbrowse,GMOD/jbrowse,nathandunn/jbrowse,GMOD/jbrowse