Use the correct hash table for pending requests
    
    The function that handled pending requests on reconnect was checking an
    orphaned global variable that was never used, redenring the whole function
    uselsess.
    
    This fixes a very nasty bug that was causing requests for which we never
    received an answer for (for example because the backend failed and was
    restarted) to be never removed and therefore causing a black hole effect for
    any other request of the same type.
    
    Fixes: https://fedorahosted.org/sssd/ticket/1229