build: remove darwin/386 as no longer supported by Go 1.15
VERSION_TAG = $(shell date +%Y%m%d)-01
VERSION_CHECK = @$(call print, "Building master with date version tag")
-BUILD_SYSTEM = darwin-386 \
-darwin-amd64 \
+BUILD_SYSTEM = darwin-amd64 \
dragonfly-amd64 \
freebsd-386 \
freebsd-amd64 \
