Python 3 support

[GreatEmerald]

Trying to run the Python server using Python 3 results in an error:

Traceback (most recent call last):
File "/opt/linux-dash/app/server/index.py", line 6, in <module>
    from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer, test as _test
ModuleNotFoundError: No module named 'BaseHTTPServer'

This seems to indicate that it has not yet been updated to work with Python 3.

[elitepleb]

A bit late, but #463 works just fine.

[yalh76]

but #463 wasn't merged, still having the same error with python3 on Debian Bullseye