[Defaulttype] RigidDeriv: fix out-of-bounds access in ctor with Vec6 (#5735)

fix out-of-bounds access

Author: fredroy

Sofa/framework/DefaultType/src/sofa/defaulttype/RigidDeriv.h

@@ -79,7 +79,7 @@ class RigidDeriv<3, real>
 
     template<typename real2>
     constexpr RigidDeriv(const type::Vec<6, real2>& v)
-        : vCenter(type::Vec<3, real2>(v[0], v[1], v[2])), vOrientation(type::Vec<3, real2>(v[4], v[5], v[6]))
+        : vCenter(type::Vec<3, real2>(v[0], v[1], v[2])), vOrientation(type::Vec<3, real2>(v[3], v[4], v[5]))
     {}
 
     template<typename real2>