SHort update:

Open SSH to your stretch installation.

issue:
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cd~
wget http://ftp.nl.debian.org/debian/pool/main/o/openssl/libssl1.0.0_1.0.2l-1~bpo8+1_amd64.deb
Now we have to install the package
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sudo dpkg -i libssl1.0.0_1.0.2l-1~bpo8+1_armhf.deb
Restart your domoticz
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2017-09-10 13:28:58.438 Domoticz V3.8153 (c)2012-2017 GizMoCuz
2017-09-10 13:28:58.438 Build Hash: 494fff7, Date: 2017-07-30 12:19:41
2017-09-10 13:28:58.438 Startup Path: /home/pi/domoticz/
2017-09-10 13:28:58.835 PluginSystem: Started, Python version '3.5.3'.
2017-09-10 13:28:58.841 Active notification Subsystems: gcm, http (2/12)
2017-09-10 13:28:58.843 WebServer(HTTP) started on address: :: with port 8080
For my test setup it is working now.