In gpk-application, when studying the details of a non-installed package, when I
go to the "Required by" tab, I get an intrusive message dialog telling me that
the package is not installed. The acutal content of the tab, "No packages",
seems perfectly sufficient, no need to disrupt the flow with a dialog.
I've fixed this and pushed it to master and stable. We'll pick this up on the
next snapshot we do. Yell if you want me to build another version as a priority.