Build dependency qt5-default no longer valid on Debian 11 "Bullseye"

[kyllingstad]

I had some trouble building Displace on Debian 11 because the package qt5-default doesn't exist in this version. Instead, I got it to work by adding libqt5core5a(>=5.6) as an alternative under Build-Depends in debian/control.

[studiofuga]

Hi @kyllingstad , thank you for reporting this.
I added a few more changes - the package mentioned is not 100% correct because the -dev package is indeed needed (qtbase5-dev) I took the occasion to fix other dependencies too, both in the Displace source and in the msqlitecpp source.

Thank you.