Fix for BusyBox 1.30 (Alpine 3.10) and above

[kriskbx]

First and foremost: Thanks a lot for this awesome tool. Been using it a lot lately. <3

Starting with BusyBox 1.30 the timeout command doesn't need the -t option anymore and therefore wait-for-it breaks on these systems:

/ # ./wait-for-it.sh 127.0.0.1:80
timeout: unrecognized option: t
BusyBox v1.30.1 (2019-06-12 17:51:55 UTC) multi-call binary.

Usage: timeout [-s SIG] SECS PROG ARGS

To fix that I added a check that removes the -t option for BusyBox versions 1.30 and up.

[cmur2]

It would be so great to have support for Alpine 3.10 👍

[neumachen]

@vishnubob looks good dude. Perhaps merge?

[KrakenTyio]

I think this MG is not valid for new and old version.
When i upgrade by MG it start work for newest alpine, but for old it start skiping timeout and print something like this

XYZ:7489
timeout: can't execute '120': No such file or directory
wait-for-it.sh: timeout occurred after waiting 120 seconds for XYZ:7489

only valid syntax on old container in docker for node12-alpine is

../tool/wait-for-it.sh ${DB_TARGET}:${DB_PORT} --timeout=0 --strict -- npm start

[blaskovicz]

@kriskbx can you please rebase?

[blaskovicz]

actually, was this fixed via ed77b63