bug #4444 fix elseif statement (MightyBranch)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #4444).

Discussion
----------

fix elseif statement

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | --

In this example of the book, the elseif block always evaluates to FALSE since $_SERVER['REQUEST_URI'] includes the query string, therefore if $uri equals to '/index.php/show' then $_GET['id'] is never set, and the list_action() is never executed.

Here I propose a fix by cleaning the query string from the URI before assigning it to $uri, using the built-in function parse_url().

Commits
-------

ab10529 fix elseif statement

book/from_flat_php_to_symfony2.rst

@@ -367,7 +367,7 @@ on the requested URI:
     require_once 'controllers.php';
 
     // route the request internally
-    $uri = $_SERVER['REQUEST_URI'];
+    $uri = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
     if ('/index.php' == $uri) {
         list_action();
     } elseif ('/index.php/show' == $uri && isset($_GET['id'])) {