Gracefully ignore exceptions when trying to register the ProtocolHandler

Diaspora.ProtocolHandler = {

  register: function() {

    if (typeof (window.navigator.registerProtocolHandler) !== "function") {

    if (!window.navigator.registerProtocolHandler) {

      return false;

    }

    var protocol = location.protocol;

    var slashes = protocol.concat("//");

    var host = slashes.concat(window.location.hostname);

    if (location.port) {

      host = host.concat(":" + location.port);

    try {

      window.navigator.registerProtocolHandler(

        "web+diaspora",

        [window.location.protocol, "//", window.location.host, "/link?q=%s"].join(""),

        document.title

      );

    } catch (_) {

      return false;

    }

    window.navigator.registerProtocolHandler("web+diaspora", host.concat("/link?q=%s"), document.title);

    return true;

  }

};