using a proxy stuck in "connecting..." state sometimes

[r10s]

this was reported a chat, i am opening this issue to collect more information and maybe make it reproducible:

I use proxy.
when I close the app and open it again, it takes time to automaticaly update the notification. (30sec or something like that) it will stock at "connecting phase"
what I do is I manually stop the proxy and restart the proxy again (inside the app)
then it goes to updating

(this is a report about android, bit it was reported to happen on iOS as well)

[link2xt]

I don't think we do anything special with proxied connections. The only thing that changes is connection establishment. The problem could be with the proxy itself and how it handles connection reuse, keepalives and so on. We don't have 30 seconds timeouts in the core, every timeout (read/write/connection) is exactly 60 seconds.

Need at least a log and rough timing with ~30 seconds accuracy according to the wall clock of what user does and what happens when.