Description of problem:
When editing data in the advanced tab I am unable to remove the information once I've saved it.  I can change the data but I can't actually remove the data.

Version-Release number of selected component (if applicable):
5.9


How reproducible:
Every Time

Steps to Reproduce:
1. Navigate to Configuration > Settings > Server: EVM (currnet) > Advanced
2. enter an IP and port (example below)
:http_proxy:
   :azure:
      :host: 10.10.10.30
      :password:
      :port: 3128
      :user:
3. click Save
4. Once saved scroll back down to that section and remove the IP and port (example below)
:http_proxy:
   :azure:
      :host:
      :password:
      :port:
      :user:
5. click Save
6. scroll down to the the http_proxy/azure settings and note that the ip and port still exist.  I can't figure out a way to actually remove this data.

Actual results:
ip and ports are not being removed

Expected results:
if I delete data it should be removed.


Additional info: