Minor Python 3 fix in pulsarhtmlutils
Add a Python 3 fix (use six.string_type for string type checking) to pulsarhtmlutils.py.
Maintenance will be performed on git.ligo.org, containers.ligo.org, and docs.ligo.org on Tuesday 23 April 2024 starting at approximately 9am PDT. It is expected to take around twenty minutes and there will be several periods of downtime throughout the maintenance. Please address any comments, concerns, or questions to the helpdesk.
Add a Python 3 fix (use six.string_type for string type checking) to pulsarhtmlutils.py.