Fix Czech Railways extractor to handle multi-leg group tickets properly
Summary:
A group ticket contains some additional "Ref" lines in the trip outline,
which confused the extractor as it tried to parse them as station names.
Reviewers: vkrause
Reviewed By: vkrause
Subscribers: kde-pim
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D22895