Adding a deprecated option to skip the DB sanity check to db_sync
interface, to give deployer a chance to execute migration script.
Without this change all migration scripts will be blocked before get
execution.
DocImpact
Change-Id: If887ac6b814879a0140dc1065a060233aee7bc82
Partial-Bug: #1279000
Related-Id: I7f271d846141ac72dde3fb0d12159b125018eb2c
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>