JSON Config set-url-pfx does not work

[oreillyjw]

Describe the issue

Running on RaspberryPi 3B+ using the json config file to set option set-url-pfx does not work. See output below from the unum generated various log files
http.log

944 2019.07.19 14:28:59 http_req: 73ebc3c8 PUT url <�<��d��d��d��d��d��d��d��d/v3/unums/<redacted-mac-address>/activate> 2264 2019.07.19 1

unum log:

944 2019.07.19 14:28:59 activate: no response
944 2019.07.19 14:28:59 activate: error, retrying in 41 sec

/etc/opt/unum/config.json

{
  "lan-if": "br-lan",
  "wan-if": "eth0",
  "set-url-pfx" : "http://localhost"
}

Saying this I was able to update the unum systemd service file to get around this.

Expected behavior

Using the config would result in the same behavior as using a command line argument.

Actual behavior

Unable to get a successfully request when using the config file for the set-url-pfx option

Steps to reproduce

1. Default installed via minim-config
2. Update /etc/opt/unum/config.json to add set-url-pfx
3. Start unum agent

Platform, version, etc

• SDK version: 2019.0719
• Runtime Platform: linux_generix build
• Build Platform: RaspberryPi 3B+