wait for /dnsmasq.pid

[robertkirkman]

• See deblobbify, replacing the system folder with several other components #72 (comment)

[robertkirkman]

just some notes about this that may be relevant to whether this should be applied or not:

With this, if dnsmasq ever fails to start completely in the future again in some situation, it would freeze the container and not allow it to progress, instead of the current behavior which is allowing it to continue while printing a warning that DNS will not work.

however, all normal situations where dnsmasq could previously fail to start completely are thought to have been fixed after the recent changes:

• Failed to start dnsmasq, host name resolution may fail [ macos arm64 ] #68
• Hostnames fail to resolve #63

so, it might be a very rare situation now. dnsmasq failing to start completely is also not the situation reported that this PR attempts to fix. If I'm not mistaken, the situation reported is simply that the current 1 second delay for dnsmasq is too short, and dnsmasq failed to activate in time to provide DNS immediately on running interactive commands in termux-docker shell.

I can't reproduce on my devices the issue this PR attempts to fix, so someone who still can will need to discuss this with me and help test this before we can decide what to do.