C client tests hang to be cancelled quite often

     [exec] Zookeeper_multi::testWatch : elapsed 2005 : OK
     [exec] Zookeeper_multi::testSequentialNodeCreateInAsyncMulti : elapsed 2001 : OK
     [exec] Zookeeper_multi::testBigAsyncMulti : elapsed 3003 : OK
     [exec] Zookeeper_operations::testAsyncWatcher1 : elapsed 54 : OK
     [exec] Zookeeper_operations::testAsyncGetOperation : elapsed 54 : OK
     [exec] Zookeeper_operations::testOperationsAndDisconnectConcurrently1 : elapsed 382 : OK
     [exec] Zookeeper_operations::testOperationsAndDisconnectConcurrently2 : elapsed 0 : OK
     [exec] Zookeeper_operations::testConcurrentOperations1 : elapsed 21127 : OK
     [exec] Zookeeper_readOnly::testReadOnly ZooKeeper server started ZooKeeper server started : elapsed 12214 : OK

     [exec] Zookeeper_multi::testWatch : elapsed 2006 : OK
     [exec] Zookeeper_multi::testSequentialNodeCreateInAsyncMulti : elapsed 2001 : OK
     [exec] Zookeeper_multi::testBigAsyncMulti : elapsed 3003 : OK
     [exec] Zookeeper_operations::testAsyncWatcher1 : elapsed 54 : OK
     [exec] Zookeeper_operations::testAsyncGetOperation : elapsed 54 : OK
     [exec] Zookeeper_operations::testOperationsAndDisconnectConcurrently1 : elapsed 387 : OK
     [exec] Zookeeper_operations::testOperationsAndDisconnectConcurrently2 : elapsed 0 : OK
     [exec] Zookeeper_operations::testConcurrentOperations1 : elapsed 22459 : OK
     [exec] Zookeeper_readOnly::testReadOnly ZooKeeper server started ZooKeeper server started : elapsed 15515 : OK
     [exec] Zookeeper_readOnly::testReadOnlyWithSSL ZooKeeper server started ZooKeeper server started : elapsed 14865 : OK