Block all scripts + Spoof <noscript> may still allow pages to redirect to "Script disabled" style dead end pages

Prerequisites

[x] I performed a cursory search of the issue tracker to avoid opening a duplicate issue
- Your issue may already be reported: Probably not, but may be related to https://github.com/uBlockOrigin/uMatrix-issues/issues/149
- [x] I also searched the existing issues at https://github.com/gorhill/uMatrix/issues
[x] This is not a support issue or a question
- Support issues and questions are handled at /r/uMatrix
I tried to reproduce the issue when...
- [x] uMatrix is the only extension
- [ ] uMatrix with default lists/settings: mostly, only * * script block was added
- [x] using a new, unmodified browser profile
[x] I am running the latest version of uMatrix (I hope)
[x] I checked the documentation to understand that the issue I report is not a normal behavior (Only superficially. Doubt this would be in the docs…)
[x] I used the logger to rule out that the issue is caused by my ruleset

Description

When scripts are entirely blocked and the "Spoof <noscript> tags when 1st-party scripts are blocked" is on, meta http-equiv="refresh" can redirect to "You have JavaScript disabled, dummy"-style pages. (Or rather: accessibility.blockautorefresh does not function).

Given that https://github.com/gorhill/uMatrix/blob/9b292304d33a44465922200efa5f8b378d0f9604/src/js/contentscript.js#L481 is being invoked, I guess this is somewhat by design. But I don't think it's desirable behaviour. It would sure be nice to get the usual firefox popup of ~"This webpage automatically redirected, we blocked, allow?".

A specific URL where the issue occurs

https://www.immowelt.de/immobilienpreise/bielefeld/wohnungspreise

The part of the page source code that's probably causing the issue:

<body>
    <!-- Tealium -->
    <script type="text/javascript">
        //<![CDATA[
        var utag_data = { "app_medienid": 0 }
            //]]>
    </script>
    <noscript>
    <meta http-equiv="refresh" content="0;url=/immobilienpreise/no-script" />
</noscript>

Steps to Reproduce

Grab myself a fresh profile: firejail --private firefox --no-remote
Install umatrix through about:addons
Navigate to some random page and block scripts on all pages
Navigate to page linked above

Ruleset

https-strict: behind-the-scene false
matrix-off: about-scheme true
matrix-off: behind-the-scene true
matrix-off: chrome-extension-scheme true
matrix-off: chrome-scheme true
matrix-off: moz-extension-scheme true
matrix-off: opera-scheme true
matrix-off: vivaldi-scheme true
matrix-off: wyciwyg-scheme true
noscript-spoof: * true
referrer-spoof: * true
referrer-spoof: behind-the-scene false
* * * block
* * css allow
* * frame block
* * image allow
* * script block
* 1st-party * allow
* 1st-party frame allow

Supporting evidence

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Your environment

uMatrix version: uMatrix 1.4.0
Browser Name and version: Firefox 77.0.1
Operating System and version: Gentoo Linux. Version e^(-iπ)

uBlockOrigin / uMatrix-issues

Block all scripts + Spoof <noscript> may still allow pages to redirect to "Script disabled" style dead end pages #270