[Users] make attachment-bar of mail-viewer visible again

[Johannes Deutsch]

Hi all,

recently i switched from evolution to claws-mail 3.8.0 and i'm quite
impressed of it's speed, the filtering system, the rss plugin...

But there have been something, that gone wrong and i need your help.

For quite some time now i'm missing the bar, that lists the attachments
in the mail-viewer. Some day i have switched this feature of, by
clicking at the top of the bar. Since then, i can't find a way to
make this bar visible again. Maybe someone of you experts can give me a
hint!?

With best regards

Johannes