Fix NOSTRIP

[EricMountain]

NOSTRIP was incorrectly coded into the debug build: it needs to be passed as a Docker build arg.

delve works better this way:

(dlv) bt
0  0x0000000000407e8e in runtime/internal/syscall.Syscall6
   at /usr/local/go/src/runtime/internal/syscall/asm_linux_amd64.s:36
1  0x0000000000407e05 in runtime/internal/syscall.EpollWait
   at /usr/local/go/src/runtime/internal/syscall/syscall_linux.go:55
2  0x00000000004371ab in runtime.netpoll
   at /usr/local/go/src/runtime/netpoll_epoll.go:118
3  0x0000000000443185 in runtime.findRunnable
   at /usr/local/go/src/runtime/proc.go:3191
4  0x00000000004442f1 in runtime.schedule
   at /usr/local/go/src/runtime/proc.go:3582
5  0x00000000004447ff in runtime.park_m
   at /usr/local/go/src/runtime/proc.go:3745
6  0x000000000046ba2e in runtime.mcall
   at /usr/local/go/src/runtime/asm_amd64.s:458

# Maybe wrong, but at least it doesn't panic:
(dlv) args
(no args)

(dlv) grs
  Goroutine 1 - User: /go/pkg/mod/github.com/go-delve/delve@v1.22.0/cmd/dlv/cmds/commands.go:898 github.com/go-delve/delve/cmd/dlv/cmds.waitForDisconnectSignal (0x9d641d) [select]
  Goroutine 2 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [force gc (idle) 156123584244879]
  Goroutine 3 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [GC sweep wait]
  Goroutine 4 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [GC scavenge wait]
  Goroutine 5 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [debug call]
  Goroutine 11 - User: /usr/local/go/src/runtime/internal/syscall/syscall_linux.go:38 syscall.RawSyscall6 (0x407e6d) (thread 24) [chan receive]
  Goroutine 18 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [finalizer wait 156123584244879]
  Goroutine 19 - User: /go/pkg/mod/github.com/go-delve/delve@v1.22.0/pkg/proc/native/proc.go:400 github.com/go-delve/delve/pkg/proc/native.(*ptraceThread).handlePtraceFuncs (0x88a357) [chan receive]
  Goroutine 20 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [debug call]
  Goroutine 21 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [debug call 156125290278278]
  Goroutine 22 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [debug call]
  Goroutine 34 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [debug call]
  Goroutine 35 - User: /usr/local/go/src/net/fd_unix.go:172 net.(*netFD).accept (0x549ea9) [IO wait]
  Goroutine 37 - User: /usr/local/go/src/runtime/sigqueue.go:152 os/signal.signal_recv (0x46a309) (thread 23)
  Goroutine 50 - User: /usr/local/go/src/runtime/proc.go:399 runtime.gopark (0x43de2e) [select]