Changes

debian: fixup: add missing libsctp dependency

I found `${libsctp:Version}` in `debian/control` of the erlang package
(https://salsa.debian.org/erlang-team/packages/erlang).  As it turns
out, this is not a standard debhelper substvar (like `${shlibs:Depends}`
or `${python3:Depends}`), but a custom one defined in `debian/rules`:

  dh_gencontrol -a -- -Vlibsctp:Version='$(LIBSCTPDEP)'

Thus in our case it yields nothing.  Use the package name instead.

Change-Id: Ia74d75e86b1436fc7dcdfa40d90c7e0c2e5648a1
Fixes: 9455ca1 ("debian: add missing libsctp dependency")