Numbered parameters in postgres flavour are substituted inside a string literal

[terazoid]

After sql is genereted, code inside if (options.numberedParameters) replaces all options.parameterCharacter occurrences with named parameters, even if options.parameterCharacter is inside a string literal.

To reproduce this bug you can use the following code:

const squel = require('squel').useFlavour('postgres');

let q = squel.update()
    .table('table')
    .set('a', '?');
console.log(q.toString());

Expected: UPDATE table SET a = '?'
Got: UPDATE table SET a = '$1'