new stable version of stiebel-isg
new stable version of stiebel-isg

Confirmed stable version of stiebel-isg adapter, due to forum-test thread: https://forum.iobroker.net/topic/39609/test-adapter-stiebel-isg-v1-6-x
ioBroker/ioBroker.repositories,ioBroker/ioBroker.repositories