Conversion fails with Java version 13

[yanokwa]

$ java -version
openjdk version "13" 2019-09-17
OpenJDK Runtime Environment (build 13+33)
OpenJDK 64-Bit Server VM (build 13+33, mixed mode, sharing)

$ xls2xform test.xslx
Traceback (most recent call last):
  File "/usr/local/bin/xls2xform", line 10, in <module>
    sys.exit(main_cli())
  File "/usr/local/lib/python2.7/site-packages/pyxform/xls2xform.py", line 175, in main_cli
    enketo=args.enketo_validate,
  File "/usr/local/lib/python2.7/site-packages/pyxform/xls2xform.py", line 48, in xls2xform_convert
    enketo=enketo,
  File "/usr/local/lib/python2.7/site-packages/pyxform/survey.py", line 858, in print_xform_to_file
    warnings.extend(odk_validate.check_xform(path))
  File "/usr/local/lib/python2.7/site-packages/pyxform/validators/odk_validate/__init__.py", line 93, in check_xform
    check_java_version()
  File "/usr/local/lib/python2.7/site-packages/pyxform/validators/odk_validate/__init__.py", line 79, in check_java_version
    major, minor, _ = java_version.split(".")
ValueError: need more than 1 value to unpack