Remove yield in extend_chain call tree
Remove yield in extend_chain call tree

This is no longer permissible, and would cause a crash for any block
with at least 20 transactions.

bitsuperlab/cpp-play,camponez/bitshares,camponez/bitshares,jakeporter/Bitshares,jakeporter/Bitshares,bitshares/bitshares,bitshares/bitshares,frrp/bitshares,bitshares/bitshares,frrp/bitshares,drltc/keyid,bitshares/bitshares-0.x,dacsunlimited/dac_play,bitshares/bitshares-0.x,Ziftr/bitshares,camponez/bitshares,FollowMyVote/bitshares,bitshares/devshares,camponez/bitshares,drltc/keyid,bitshares/bitshares-0.x,FollowMyVote/bitshares,bitshares/devshares,dacsunlimited/dac_play,jakeporter/Bitshares,RemitaBit/Remitabit,dacsunlimited/dac_play,RemitaBit/Remitabit,drltc/keyid,FollowMyVote/bitshares,FollowMyVote/bitshares,FollowMyVote/bitshares,frrp/bitshares,jakeporter/Bitshares,bitsuperlab/cpp-play,bitshares/bitshares-0.x,bitshares/devshares,Ziftr/bitshares,bitsuperlab/cpp-play,RemitaBit/Remitabit,jakeporter/Bitshares,bitshares/bitshares-0.x,dacsunlimited/dac_play,FollowMyVote/bitshares,bitshares/bitshares,bitshares/devshares,RemitaBit/Remitabit,frrp/bitshares,bitsuperlab/cpp-play,bitshares/bitshares,RemitaBit/Remitabit,jakeporter/Bitshares,bitshares/bitshares-0.x,Ziftr/bitshares,bitsuperlab/cpp-play,bitsuperlab/cpp-play,bitshares/devshares,Ziftr/bitshares,camponez/bitshares,frrp/bitshares,RemitaBit/Remitabit,bitshares/bitshares,bitshares/devshares,dacsunlimited/dac_play,frrp/bitshares,drltc/keyid,dacsunlimited/dac_play,camponez/bitshares