uBlock Origin v1.25.2 + VPN add on cause DNS leaks

[nobura]

Prerequisites

• I verified that this is not a filter issue
  • Filter issues MUST be reported at filter issue tracker
• This is not a support issue or a question
  • Support issues and questions are handled at /r/uBlockOrigin
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
• I tried to reproduce the issue when...
  • uBlock Origin is the only extension
  • uBlock Origin with default lists/settings
  • using a new, unmodified browser profile
• I am running the latest version of uBlock Origin
• I checked the documentation to understand that the issue I report is not a normal behavior

Description

[Description of the bug or feature]

A specific URL where the issue occurs

[A specific URL is MANDATORY for issue happening on a web page, even if it happens "everywhere"]

Steps to Reproduce

1. install dan start browsec https://addons.mozilla.org/en-US/firefox/addon/browsec/ or hoxx vpn https://addons.mozilla.org/en-US/firefox/addon/hoxx-vpn-proxy/

2. use DNS leaks test site
   https://www.expressvpn.com/dns-leak-test

"DNS leaks" exposed your location. when disable the uBlock Origin from add on, the problem is gone.

Expected behavior:

[What you expected to happen]

Actual behavior:

[What actually happened]

Your environment

• uBlock Origin version: 1.25.3rc0
• Browser Name and version: firefox 74
• Operating System and version: windows 1909 x64

[gwarser]

Duplicate of #911