Revert "Disable debug messages when running unit tests"

This reverts commit 56edda0d1840da1ccfcd7c35df397251ddb779db.

Another patch (commit-id: df96a03e6c74f1fceb4525900bca885307907b79) to
fix the same issue with less intrusive consequences was already merged
into master. There's still benefit to have debug logs if this does not
make gate jobs fail, so revert to previous setting value.

Related-Bug: 1316610
Change-Id: I9b57369027e1e43bed1bde4d971dee9fb7a26a47
Make VPNaaS 'InUse' exception more clear

In case IpSecPolicy or IKEPolicy is updated while VPN connection that uses it
is already established, IPsecPolicyInUse or IKEPolicuInUse is raised.
Need to clarify their messages to emphasize that policies can't be updated
because they are used by established connection.

Change-Id: I259f9b8bcff7f8ec13ac630285f6e881c6653309
Closes-Bug: #1315809
Merge "Make VPNaaS 'InUse' exception more clear"
Merge "Revert "Disable debug messages when running unit tests""