fix compatibility with Python 3.9 by renaming fancy root logger

[boegel]

Requires because of changed behavior in Python's getLogger function, see python/cpython#15077

Fix for:

 >> python -m easybuild.main --version
Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.9.0/x64/lib/python3.9/runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/opt/hostedtoolcache/Python/3.9.0/x64/lib/python3.9/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/home/runner/work/easybuild-framework/easybuild-framework/easybuild/main.py", line 46, in <module>
    from easybuild.tools.build_log import EasyBuildError, print_error, print_msg, stop_logging
  File "/home/runner/work/easybuild-framework/easybuild-framework/easybuild/tools/build_log.py", line 191, in <module>
    del _init_fancylog.manager.loggerDict[_init_fancylog.name]
KeyError: 'root'

[ocaisa]

Looks sane to me

[ocaisa]

Seems like problem solved:

(py39) [ocaisa@generoso ~]$ python -m easybuild.main --version
This is EasyBuild 4.3.1.dev0 (framework: 4.3.1.dev0, easyblocks: 4.3.1.dev0) on host generoso.