Set kombu_reconnect_delay to 5.0

Set delay to 5.0 to recover channel errors on highly loaded environments.

depends on:

https://gerrit.mirantis.com/#/c/16134/
https://gerrit.mirantis.com/#/c/16135/
https://gerrit.mirantis.com/#/c/16157/

but can be safely merged (option will be ignored)

Change-Id: Ibec002828b785282221fa6d2827163a2deb0e627
Partial-Bug: 1322259