Disable Rules Test Update

[zoracon]

This is directly off of the work done in #11616,
The only thing I added here was to disable the ruleset if all targets turn out to be problematic

[zoracon]

@Hainish Requesting review when you get a chance to look it over

[zoracon]

I also realize my text editor seemed to reformat this file for some reason :/. So I will list the function i changed here:
https://github.com/EFForg/https-everywhere/pull/17000/files#diff-db13e72ba2cc41fb2fc62d0cc64540c3R216

[Bisaloo]

https://github.com/EFForg/https-everywhere/pull/17000/files?w=1

Diff without the whitespace changes. Just add ?w=1 to the URL 😉

[zoracon]

@Bisaloo Thanks for the tip! Didn't know about that trick

[cschanaj]

IMHO, it is better to comment out the failing target instead of removing them completely.

[Hainish]

Thanks - just a few python3-friendly changes requested.

[zoracon]

@Hainish Applied the format changes for more up to date conventions, asking for one more once over before merge

[Bisaloo]

Fixes #1998

[cschanaj]

AFAIK, full-fetch-test will re-activate previously disabled rulesets on subsequent runs. It might be even better if we could use comment patterns which can be easily reverted, e.g.

<!-- target host="example.com" **/*-->

See https://github.com/EFForg/https-everywhere-full-fetch-test/blob/4ca85e146c86fd35c7810fb763360750f6085fe3/test.sh#L4

[Hainish]

Once these two issues are resolved I'm ready to merge.