Fix a bug in internalLockLoop(), where startTime is never updated.

[yh1213]

In Java version of curator:

if ( millisToWait != null )
    {
         millisToWait -= (System.currentTimeMillis() - startMillis);
        // start time is updated here
        startMillis = System.currentTimeMillis();
        if ( millisToWait <= 0 )
         {
             doDelete = true;    // timed out - delete our node
             break;
          }
           wait(millisToWait);
     }

[basvanbeek]

Thanks for the PR. Can you please add a test that would fail for the current code but will succeed for this fix?