BUG: mutex already within ossim

Code/IO/otbDEMHandler.cxx

@@ -73,9 +73,9 @@ DEMHandler
   ossimGpt ossimWorldPoint;
   ossimWorldPoint.lon=geoPoint[0];
   ossimWorldPoint.lat=geoPoint[1];
-  m_Mutex.Lock();
+//   m_Mutex.Lock();
   height=m_ElevManager->getHeightAboveMSL(ossimWorldPoint);
-  m_Mutex.Unlock();
+//   m_Mutex.Unlock();
   return height;
 }