add namespaces in WOLF_REGISTER_SENSOR macro

src/sensor_factory.h

@@ -226,8 +226,8 @@ inline std::string Factory<SensorBase,
 }
 
 #define WOLF_REGISTER_SENSOR(SensorType, SensorName) \
-  const bool SensorName##Registered = \
-    wolf::SensorFactory::get().registerCreator(SensorType, SensorName::create); \
+  namespace wolf{ namespace{ const bool SensorName##Registered = \
+    SensorFactory::get().registerCreator(SensorType, SensorName::create); }}\
 
 } /* namespace wolf */