Update to upstream version 1.7.1, build fix with /tmp mounted noexec

Details:

• Update to upstream version 1.7.1
• go puts temporary build artefacts into TMPDIR. This caused build issues when the port is built on a system where /tmp is mounted noexec. Now the port uses TMPDIR=WRKDIR
• Update maintainer's e-mail address to me@enriquefynn.com

PR: 221913
Submitted by: peter@icebear.net, enriquefynn@gmail.com (maintainer)
MFH: 2017Q4