otb dependency on libqwt5-qt

[Gudjon I. Gudjonsson]

Hi

I am wondering about the qwt dependencies of the otb source.

otb has a build dependency on libqwt-qt5-dev (Qwt version 6)

but

libotb-dev depends on libqwt5-qt4-dev (Qwt version 5)

I am trying to reduce the dependencies on Qwt5 and later remove the package.
Is there any reason for using the dependency on Qwt5 instead of Qwt6.

Regards
Gudjon