libdockapp SONAME bump .2 -> 3

[Jani Juhani Sinervo]

Hey,

I'm updating libdockapp to version 0.7.3 in Rawhide. The only two
dependencies of this package are `wmacpi`, which I will take care of
rebuilding and fixing, and `wmvolman` which will remain FTBFS until the
maintainer changes it, since the libdockapp upstream has moved the
header files to its own subdirectory of /usr/include.

Regards,
Jani Sinervo