Run esecannaserver via nohup(1) to prevent it from dying when it gets

a SIGHUP, like when the rc script is invoked from within script(1),
e.g. in portupgrade(1)'s AFTERINSTALL hook.  This is just a workaround
and I'm investigating how esecannaserver fails to ignore a SIGHUP.

Approved by:	portmgr (will, kris and self)

japanese/esecanna/files/esecanna.sh

@@ -18,7 +18,7 @@ start)
 	if [ -x $esecannaserver ]; then
 	    rm -f /tmp/.iroha_unix/IROHA
 	    echo -n ' esecanna: '
-	    $esecannaserver
+	    nohup $esecannaserver
 	fi
 	;;
 stop)