[numerics] fix bug when A is not given in ConvexQP_ADMM
[numerics] fix bug when A is not given in ConvexQP_ADMM

siconos/siconos,fperignon/siconos,fperignon/siconos,siconos/siconos,bremond/siconos,siconos/siconos,fperignon/siconos,radarsat1/siconos,bremond/siconos,bremond/siconos,fperignon/siconos,bremond/siconos,fperignon/siconos,radarsat1/siconos,radarsat1/siconos,radarsat1/siconos,radarsat1/siconos,bremond/siconos,siconos/siconos