autohelp: Remove trailing spaces from help strings

Some help strings have a trailing space that make our tests fail. These
spaces should be removed from the help strings in the projects, but it
takes time and we often end up editing manually.

Help strings from the oslo incubator might already have been fixed but
not yet imported in the projects, so no proper solution exists in this
case.

Change-Id: I606f46b23a4c5a5114bb5577273657fdf4fa5295