FS-6250 fix regression from 7efeabbd, don't discrimiate against people that have s as the first character in their user names

FS-5888 --resolve Rather than changing the default behavior I've updated the log line to be more accurate. Also fixed the problem where the delay was being overwritten.

Pre-jessie versions of Debian's mk-build-deps tool rely on libraries
that do not correctly parse debian/control, so we have to clip it down
to a smaller subset of the format to build on e.g. wheezy.