in filter.py::read_priority_scores(), only split by tab if a tab is present in the line
in filter.py::read_priority_scores(), only split by tab if a tab is present in the line

in filter.py::read_priority_scores(), only split by tab if a tab is present in the line, to allow backward compatibility with space-delimited files

nextstrain/augur,nextstrain/augur,blab/nextstrain-augur,nextstrain/augur