Fix false positives

[sdushantha]

• fixed freeCodeCamp false positive
• fixed LibraryThing false positive
• removed Zhihu due to false positives, closes Zhihu false positive #2153

[ppfeister]

As long as those fixes work, this can be merged

The failed tests can be ignored. Reading the log, the only failure is the pentestit probe that was swapped out in #2187. All other tests pass.

[sdushantha]

@ppfeister There is a merge conflict that needs to be fixed. I'll do it in the next 24 hours

[ppfeister]

I can just 3wm it locally if needed, just takes a few seconds @sdushantha

[sdushantha]

@ppfeister If you've got time, feel free to do it