Fix 'set-constant' — setProxyTrap()

[AdamWr]

Currently it doesn't work correctly for falsy values.

Steps to reproduce:

1. Add this rule:

example.org#%#//scriptlet('set-constant', 'foo.bar.test', 'true', '', '', 'true')

2. Go to - https://example.org/
3. In browser console run:

Code:

foo = {
  bar: {
    abc: {}
  }
};
console.log('Original foo.bar - foo.bar.test:', foo.bar.test);
foo.bar = {
  abc: {},
};
console.log('Rewritten foo.bar - foo.bar.test:', foo.bar.test);

or

Code:

foo = {
  bar: {
    abc: {}
  }
};
console.log('Original foo.bar - foo.bar.test:', foo.bar.test);
foo.bar = {
  abc: {},
  test: false,
};
console.log('Rewritten foo.bar - foo.bar.test:', foo.bar.test);

foo.bar.test should returns true.

Probably currentObj && should be removed from:

Scriptlets/src/scriptlets/set-constant.js

Line 320 in 2f91f88

if (currentObj && index === array.length - 1 && currentObj !== constantValue) {