Remove problematic initialiser altogether.
Remove problematic initialiser altogether.

There was no need for this base-class initialiser except to avoid a
warning in some very old gcc versions, so might as well get rid of it
altogether.

Also, documented the problem so we don't fall for it again.

jtv/libpqxx,jtv/libpqxx,jtv/libpqxx,jtv/libpqxx