Fix build of databases/soci w/ clang 4.0 and later and on arm6, arm7.
Adds upstream patch to fix

backends/mysql/session.cpp:202:22: error: ordered comparison between pointer and zero ('int *' and 'int')

if (port < 0)

PR: 222651 216074
Reported by: jbeich, Neel Chauhan
Reviewed by: jlaffaye
Approved by: tcberner (mentor)
Obtained from: upstream
Differential Revision: https://reviews.freebsd.org/D13769