Revert "CLOUDSTACK-4540: Set execute.in.sequence.network.element.commands=true by default"

This reverts commit 62be5fad122e8e8c71e5fb185390af2a5b79be25.

Refer to the latest comment in the bug.
CLOUDSTACK-5831: return quiescevm field in volumeresponse
Merge remote-tracking branch 'origin/4.3' into 4.3