Fix: ZoneSync delays in some installations caused problems

[route443]

• Fix: ZoneSync delays in some installations caused problems

  Fix is slowing down the request processing in case the zone sync is not fast enough. This issue may occur in environments where NGINX cluster nodes can randomly process requests from user agents and there may be a situation where node "A" successfully received a token, and node "B" receives the next request in less than zone_sync_interval.
  Introduced zone_sync_leeway variable that specifies the maximum timeout for synchronizing ID tokens between cluster nodes. The request doesn't wait until it reaches the timeout, if the "session_jwt" variable "appeared" in key-value database before the timeout expires, the request will be released.

• Fix: Double URL encoding in proxy upstream after internalRedirect

  In some cases the r.internalRedirect(uri) will double encode the URI. This problem may occur if OIDC module needs to update the set of tokens using the refresh token and redirect the user agent to the original request URI.

[alebastr]

LGTM, but can I convince you to make a cleaner split between the two independent changes?
I.e. commit 1 - introduce retryOriginalRequest and start using it, commit 2 - add waitForSessionSync.