tango/pytango_pprint.py: Use correct syntax for comparing object contents
We are not interested in the object type but the object contents.
The warning with python 3.8:
/home/firma/devel/pytango/build/lib.linux-x86_64-3.8/tango/pytango_pprint.py:54: SyntaxWarning: "is" with a literal. Did you mean "=="?
Something I found while testing !423 (merged).