Change qpid_heartbeat default.
    
    The default value of qpid_heartbeat of 5 seconds is unnecessarily
    aggressive.  Change it to 60 seconds to reduce the possibility of
    getting disconnected from qpidd under normal circumstances.
    
    Fix bug 1050661.
    
    Change-Id: I9525e74f96314c2c9183d6b10cf503936c81f589