generate_connection-json.sh contains a configuration error

Hi everyone,

please note that in the master branch the file generate_connection-json.sh lines 43 and 55 it says

`"url": "grpcs://${MF_HOST}:7050",`

this is not correct (the rest api itself is not a gRPC host).The corresponding orderers or peers should be inserted her e.g. orderer.myorg.net:7050 or peer.myorg.net:7050 

Best
Razvan