[1.x] Update Sail script to only exit if Main Exits

[mellester]

This is a small change that should help people who like to run e2e tests in containers defined in there docker-compose or any other short lived container.
This patch changes the behavior of Laravel sail to only shutdown the containers if and only if the main PHP containers goes down.
before this patch if any service defined docker-compose.yaml would shutdown for any reason. so would all other containers upon excuting any sail command

Which meant that if you would try to Debug or restart that one service.
for example if you would like to inspect the logs of that container with for example sail logs <servicename>
it would shutdown all containers because it found a stopped container.
This patch should change this behavior to only stop the stack if the main service goes down

[mellester]

Reupload of pull request #102 to this branch on suggestion of @driesvints