Incorrect hyphen placement in `URL_REGEX` was allowing it to match more
characters than intended. In a regex character class, a literal hyphen
can only appear as the first character in the class, or it will be
interpreted as the delimiter of a range of characters.
The issue fixed here caused the range of characters from `[$-_]`
be treated as valid URL characters, instead of the intended set of three
characters `[-_$]`. The incorrect range interpretation inadvertantly
included most ASCII punctuation, most importantly the angle brackets,
square brackets, and single quote that the expression uses
to mark the end of a match.
This causes the expression to match a URL that has a "hostname" portion
beginning with one of the intended "stop parsing" characters. For
example:
```
https://<b>www</b>.example.com/ # MATCHES but should not
https://[for example] # MATCHES but should not
scheme='https://' # MATCHES, including final quote, but should not
```
Some test cases have been added to the `URL_REGEX` assert in
archivebox.parsers to cover this possibility.
c039ef05b3