message: [bugfix] Making tier two thread interruptable.
diff: #include "swifttx.h"
  #include "util.h"
  +#include <boost/thread/thread.hpp>
  #define MN_WINNER_MINIMUM_AGE 8000 // Age in seconds. This should be > MASTERNODE_REMOVAL_SECONDS to avoid misconfigured new nodes in the list.
  @@ -868,9 +869,15 @@ void ThreadCheckMasternodes()
  unsigned int c = 0;
  + try {
  while (true) {
  - MilliSleep(1000);
  + if (ShutdownRequested()) {
  + break;
  + }
  +
  + MilliSleep(1000);
  + boost::this_thread::interruption_point();
  // try to sync from all available nodes, one step at a time
  masternodeSync.Process();
  @@ -888,4 +895,7 @@ void ThreadCheckMasternodes()
  }
  }
  }
  + } catch (boost::thread_interrupted&) {
  + // nothing, thread interrupted.
  + }
  }
  