rdf2dot script fails due to deprecated cgi module

[arnikz]

RDFLib Version: 5.0.0

Traceback (most recent call last):
  File "/home/arni/local/miniconda3/envs/rdf/bin/rdf2dot", line 8, in <module>
    sys.exit(main())
  File "/home/arni/local/miniconda3/envs/rdf/lib/python3.8/site-packages/rdflib/tools/rdf2dot.py", line 131, in main
    rdflib.extras.cmdlineutils.main(rdf2dot, _help)
  File "/home/arni/local/miniconda3/envs/rdf/lib/python3.8/site-packages/rdflib/extras/cmdlineutils.py", line 67, in main
    target(g, out, args)
  File "/home/arni/local/miniconda3/envs/rdf/lib/python3.8/site-packages/rdflib/tools/rdf2dot.py", line 103, in rdf2dot
    fields[sn].add((qname(p, g), formatliteral(o, g)))
  File "/home/arni/local/miniconda3/envs/rdf/lib/python3.8/site-packages/rdflib/tools/rdf2dot.py", line 74, in formatliteral
    v = cgi.escape(l)
AttributeError: module 'cgi' has no attribute 'escape'

Replacing cgi with html module should fix this issue.