[#2420] Call readICatUserLogging after loading DVM

Fixes #2420.

Delay the call to readICatUserLogging till after loading the DVM set.

Otherwise, use of $userNameClient breaks acAclPolicy rules break, as these are
loaded already from rsGenQuery invoked as part of readICatUserLogging.
Merge pull request #2421 from nesi/master

[#2420] Call readICatUserLogging after loading DVM