История изменений

тогда, наверное, это

You could edit the prefs.js file and add user_pref(«network.protocol-handler.app.http», «/usr/bin/firefox»); (replacing /usr/bin/firefox with the appropriate path) or use the config editor to add that setting. Use Tools -> Options -> Advanced -> General -> Config editor to launch the config editor, right click on its listing, select New, select String, enter network.protocol-handler.app.http and then the complete path to whatever browser you want to use. If the setting already exists just double click on the setting to change the path.

тогда, наверное, это