pics: only add l2 if lambda > 0.
pics: only add l2 if lambda > 0.

mjacob75/bart,frankong/bart,frankong/bart,mrirecon/bart,mrirecon/bart,sdimoudi/bart,sidward/bart,frankong/bart,sidward/bart,sdimoudi/bart,mjacob75/bart,sdimoudi/bart,sidward/bart,mjacob75/bart,mrirecon/bart,Takishima/bart,mjacob75/bart,sdimoudi/bart,frankong/bart,mjacob75/bart,Takishima/bart,sidward/bart,Takishima/bart,mrirecon/bart,frankong/bart,Takishima/bart,sdimoudi/bart,sidward/bart,mrirecon/bart,Takishima/bart