Ticket 49732 - Optimize resource limit checking for rootdn issued searches
    
    Description:  When performing a search as the Directory Manager resource limits
                  should not apply. So there is no need to "get" the limits if its
                  a Directory Manager initiated search. I'm seeing around 2% performance
                  increase when we skip getting the resource limits.
    
    https://pagure.io/389-ds-base/issue/49732
    
    Reviewed by: tbordaz (Thanks!)
    
    Signed-off-by: Mark Reynolds <mreynolds@redhat.com>