cmd/coordinator: don't skip the main go repo on freebsd-arm-paulzhol builder
cmd/coordinator: don't skip the main go repo on freebsd-arm-paulzhol builder

Fixes golang/go#21403

Change-Id: Iaef6fe2b10482adbfe3921e46defc1d59759f8d0
Reviewed-on: https://go-review.googlesource.com/55094
Reviewed-by: Sarah Adams <2b342d1c32491b4e7587e4a0e291a5f0f95d4167@google.com>

golang/build,golang/build,golang/build,golang/build