Add solution for Firefox no longer proxying localhost at all

webgoat-lessons/http-proxies/src/main/resources/lessonPlans/en/HttpBasics_ProxyIntro2.adoc

@@ -1,11 +1,23 @@
 == HTTP Proxy Setup: The Browser
 
+*Important: Firefox no longer proxies traffic for localhost (127.0.0.1) due to security reasons*.
+The are two options to bypass this restriction:
+
+- Use the host name of your machine instead of `localhost`, you can find or add a host name in `/etc/hosts` on Linux and MacOSX and `C:\Windows\System32\drivers\etc` on Windows
+- Set the preference `network.proxy.allow_hijacking_localhost` (accessible through the `about:config` page) must be set to `true.
+
+The first option is the preferred one, but it might be that for some reason you are unable to use this option you can fallback to the second one.
+
+{nbsp} +
+
+
 There are many plugins to manage this, but this will show you how to do this manually in Firefox and Chrome.
 This will send all of your traffic to the proxy. Since we haven't set up a trusted cert. yet, that may cause issues with any https requests. More on that in a bit though. Let's stick to basics for now:
 
+
 === Firefox Proxy Config
 
-. Go to your Firefox Preferences (Mac, Linux) or Options (Windows) from the menu.
+. Go to your Firefox Preferences (Mac, Linux) or Options (Windows) from the menu.`
 . Select _Advanced_ on the left
 . Select _Network_ in the in Advanced Pane
 . Click _Settings_