Fix #138

[ewilly]

Problem

• cf #138
• if a subfolder exist in conf directory the bind_public_ip test:
  1. produce an error
  2. dont test file in it

Solution

• lookup for file only including those in subfolder

PR checklist

• [X] PR finished and ready to be reviewed

[Psycojoker]

idk the functional part of this code but the python part looks very correct and not buggy

[OniriCorpe]

so LGTM