Backport of "adaptivedemux: do not retry downloads during shutdown." into 1.16
Backport of !427 (merged) "adaptivedemux: do not retry downloads during shutdown.".
Commits:
- 659d76a6 adaptivedemux: remove some deadlocks using webkitwebsrc.
Backport of !427 (merged) "adaptivedemux: do not retry downloads during shutdown.".
Commits: