Fix conflict with NoScript

See #748.
NoScript overrides getShortcutOrURIAndPostData() with only one argument and breaks getShortcutOrURIAndPostData.length detection

noscript.jar\content\noscript\noscriptBM.js
```js
  delayedInit: function() {
    for each (let f in ["getShortcutOrURIAndPostData" /* Fx >= 25 */, "getShortcutOrURI"]) {
      if (f in window) {
        let getShortcut = window[f];
        window[f] = function(aURL) {
          if ("gURLBar" in window && window.gURLBar) {
            window.gURLBar.originalShortcut = aURL;
          }
          return getShortcut.apply(window, arguments);
        }
        break;
      }
    }
```