FairMQ: Add test for example/advanced/Region.

Also fix a regression in nanomsg transport.

examples/advanced/Region/FairMQExampleRegionSampler.h

@@ -33,6 +33,8 @@ class FairMQExampleRegionSampler : public FairMQDevice
 
   private:
     int fMsgSize;
+    uint64_t fMaxIterations;
+    uint64_t fNumIterations;
     FairMQUnmanagedRegionPtr fRegion;
     std::atomic<uint64_t> fNumUnackedMsgs;
 };