Ticket #542 - Cannot dynamically set nsslapd-maxbersize
    
    Fix description: Based on the proposal made by rmeggins@redhat.com
    in the ticket #542, this patch sets maxbersize every time before
    reading the client input from the socket.
    
    If the incoming ber size is larger than maxbersize, access log logs:
    [..] conn=# op=-1 fd=64 closed error 34 (Numerical result out of range) - B2
    And the error log logs:
    [..] connection - conn=# fd=# Incoming BER Element was too long, max
    allowable is # bytes. Change the nsslapd-maxbersize attribute in
    cn=config to increase.
    
    https://fedorahosted.org/389/ticket/542
    
    Reviewed by Rich (Thank you!!)
    (cherry picked from commit cce46be3b8cc12ccef8c34024a6ade2c07e28273)