Make deploy_newnode.sh autodetect bootnode

This is done by reading bootnode address from the newest bootnode log
file in tmp_log.

test/deploy_newnode.sh

@@ -116,6 +116,25 @@ HMY_OPT=
 HMY_OPT2=
 HMY_OPT3=
 
+unset -v latest_bootnode_log
+latest_bootnode_log=$(ls -tr "${ROOT}"/tmp_log/log-*/bootnode.log | tail -1)
+case "${latest_bootnode_log}" in
+"")
+	echo "cannot determine latest bootnode log"
+	exit 69
+	;;
+esac
+unset -v bn_ma
+bn_ma=$(sed -n 's:^.*BN_MA=::p' "${latest_bootnode_log}" | tail -1)
+case "${bn_ma}" in
+"")
+	echo "cannot determine boot node address from ${latest_bootnode_log}"
+	exit 69
+	;;
+esac
+echo "autodetected boot node multiaddr: ${bn_ma}"
+HMY_OPT2="-bootnodes ${bn_ma}"
+
 for i in 0{1..9} {10..99}
 do
     echo "launching new node $i ..."