Wrong tooltip for rooms in substitution table

In the tooltip is shown the first room two times and the second one is missing.

added part::frontend source::customer type::bug labels

changed title from Wrong tooltip in substitution table to Wrong tooltip for rooms in substitution table

created merge request !87 (merged) to address this issue

mentioned in merge request !87 (merged)

assigned to @hansegucker

closed with merge request !87 (merged)

mentioned in commit 0ea0b2cb