(Bug 3402) Serials issue name not escaped when passed forward to routing slip

(Bug 3402) Serials issue name not escaped when passed forward to routing slip

The issue descriptor was not being escaped before being passed on to the
routing slip, causing truncation.  It's truly impossible to know for sure
what will be there, so uri_escape-ing seemed the best way to ensure that
it gets handed forward and makes it all the way to the printable slip.

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>
Signed-off-by: Henri-Damien LAURENT <henridamien.laurent@biblibre.com>