Degraded functionality when using `HIDE_REFERER` option

**Describe the bug**
If I set the `HIDE_REFERER` environment variable to true, not only password login, but also core features like adding a new watch or setting the filter will not work anymore, as I will get the error described in #1255.

By setting this to false, the web interface will work as expected.
However that is not a solution, because as I understand, this way the service will let external services to know about the hostaname of the changedetection service ran by the user. On one hand this is leaking information that may be sensitive, but the monitored website may also restrict access if they determine that these are automated requests done by a change detection and logging software.

**Version**
v0.41

**To Reproduce**

Steps to reproduce the behavior:
1. run changedetection.io with the `HIDE_REFERER=true` environment variable
2.

! ALWAYS INCLUDE AN EXAMPLE URL WHERE IT IS POSSIBLE TO RE-CREATE THE ISSUE - USE THE 'SHARE WATCH' FEATURE AND PASTE IN THE SHARE-LINK!

**Expected behavior**
Password protection, adding watches, setting watch filters and other features should work without leaking information to the monitored websites.

**Screenshots**


**Desktop (please complete the following information):**
- OS: Windows
- Browser Firefox
- Version v0.41

**Additional context**
It seems as if with `HIDE_REFERER=true`, GET requests to the changedetection service are always served as expected, and all POST requests consistently return with HTTP 400.