Fix dockstring in default_config due to H402 rule

When we run pep8 tests in a root project folder, flake8 with default
settings also checks .ropeproject/ folder and finds two errors there.

pep8 runtests: commands[0] | flake8
./.ropeproject/config.py:5:1: H402  one line docstring needs punctuation.
./.ropeproject/config.py:84:1: H402  one line docstring needs punctuation.

So I fixed these dockstrings to avoid such confusion