fix warnings

include/sot/core/feature-pose.hh

src/feature/feature-point6d-python.h

src/feature/feature-point6d-relative-python.h

src/feature/feature-point6d-relative.cpp

src/feature/feature-point6d.cpp

src/feature/feature-pose.cpp

src/matrix/vector-to-rotation-python.h

src/matrix/vector-to-rotation.cpp

tests/features/test_feature_point6d.cpp