Fixes printer-manager error messages from exceeding window dimenssions

Summary:
Set setWordWrap(true) on the various KMessageWidget used.
I could not test it as I was not able to produce an error message.

BUG: 415444

Test Plan: ?? Ideas

Reviewers: broulik, ngraham

Reviewed By: ngraham

Subscribers: ngraham, kde-utils-devel

Differential Revision: https://phabricator.kde.org/D28548