Ensure kombu channels are closed
Ensure kombu channels are closed

Kombu doesn't always close channel we created for us.
So we must ensure they are closed correctly.

Closes-bug: #1406629

Change-Id: I7c1b31c37ac75dd4fded4d86f046c18f9c2dd7b8

zhurongze/oslo.messaging,dims/oslo.messaging,stevei101/oslo.messaging,apporc/oslo.messaging,dukhlov/oslo.messaging,dukhlov/oslo.messaging,stevei101/oslo.messaging,zhurongze/oslo.messaging,isyippee/oslo.messaging,dims/oslo.messaging,magic0704/oslo.messaging,ozamiatin/oslo.messaging,hkumarmk/oslo.messaging,isyippee/oslo.messaging,apporc/oslo.messaging,magic0704/oslo.messaging,ozamiatin/oslo.messaging,hkumarmk/oslo.messaging