Fix #592: Add try-catch around port string-to-int conversion.
Fix #592: Add try-catch around port string-to-int conversion.

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