No longer add debug symbols to release build

* admin/nt/dist-build/build-zips.sh: Remove -g3 from release build and
  install with install-strip
1 job for master in 18 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Test
failed #2016
test-all

00:00:18

 
Name Stage Failure
failed
test-all Test There has been a runner system failure, please try again
Running with gitlab-runner 11.6.0 (f100a208)
on gitlab-runner-docker cff9d373
Using Docker executor with image debian:stretch ...
Pulling docker image debian:stretch ...
Using docker image sha256:8d31923452f8b79ae91b01568d28c90e7d667a9eaff9734c6faeb017b0efa8d0 for debian:stretch ...
ERROR: Job failed (system failure): Error response from daemon: failed to start shim: exec: "docker-containerd-shim": executable file not found in $PATH: unknown (executor_docker.go:1018:7s)