Avoid KeyError: 'PATH_INFO' errors

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I use bottle often and in many of the applications I get frequent tracebacks:

Traceback (most recent call last):
  File "/src/pvoproxy/venv/lib/python3.11/site-packages/bottle.py", line 863, in _handle
     path = environ['bottle.raw_path'] = environ['PATH_INFO']
                                         ~~~~~~~^^^^^^^^^^^^^
KeyError: 'PATH_INFO'

This PR fixes that.