In User Service qryuser.go, tx.Rollback() is called without error checking

[codegold79]

Consider the best way to handling tx.Rollback() calls in qryuser.go. We can:

• [ ] log
• [ ] retry
• [ ] do nothing different
• [ ] check what other people do and implement that

If logging has been decided as the way to go, then this issue will be blocked by #123.