Correct "AddOn_Connection_String" in the README example

Current value for AddOn_Connection_String in the example operations
to add and modify host are "" and "Moooodify" respectively.
This patch changes them to "intel:https://192.168.1.1:9999",
according to comment
https://github.com/OpenAttestation/OpenAttestation/issues/8#issuecomment-28330514