Revert "[kernel] fix bug with non-initalized interactions"
Revert "[kernel] fix bug with non-initalized interactions"

This reverts commit 18fc39c13c31cd35ea19c4581f5711e24ca40d7d.

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