[c++] Fix bug in initialization of several tasks, which did not initializa the...

[c++] Fix bug in initialization of several tasks, which did not initializa the reference. This was making the software crash in case the user forgot to set a reference for the task.

src/tasks/task-angular-momentum-equality.cpp

@@ -40,6 +40,7 @@ namespace tsid
       m_L.setZero(3);
       m_dL.setZero(3);
       m_dL_des.setZero(3);
+      m_ref.resize(3);
     }
 
     int TaskAMEquality::dim() const

src/tasks/task-com-equality.cpp

@@ -38,6 +38,7 @@ namespace tsid
       m_p_com.setZero(3);
       m_v_com.setZero(3);
       m_a_des_vec.setZero(3);
+      m_ref.resize(3);
       m_mask.resize(3);
       m_mask.fill(1.);
       setMask(m_mask);      

src/tasks/task-cop-equality.cpp

@@ -31,6 +31,7 @@ m_constraint(name, 3, 3),
 m_contact_name("")
 {
   m_normal << 0, 0, 1;
+  m_ref.setZero();
 }
 
 void TaskCopEquality::setContactList(const std::vector<std::shared_ptr<ContactLevel> >  *contacts)