.jshintrc

help: fix a py3 error interpolating Set into b'%s'

I can't reproduce it, but a coworker hit this with `hg help -v` with 6.2.3:

    ...
      File "mercurial\help.pyc", line 865, in helplist
    TypeError: %b requires a bytes-like object, or an object that implements __bytes__, not 'set'

I can confirm that the original expression fails in `hg debugshell`, and the new
one works.  The second instance was found by searching for "%s", but PyCharm
detects a lot of variables as Any type, so I have no idea if there are other
lurking problems.

{
    // Enforcing
    "eqeqeq"        : true,     // true: Require triple equals (===) for comparison
    "forin"         : true,     // true: Require filtering for..in loops with obj.hasOwnProperty()
    "freeze"        : true,     // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
    "nonbsp"        : true,     // true: Prohibit "non-breaking whitespace" characters.
    "undef"         : true,     // true: Require all non-global variables to be declared (prevents global leaks)

    // Environments
    "browser"       : true      // Web Browser (window, document, etc)
}