minor #5597 [CreateFramework] don't override existing variables (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
----------

[CreateFramework] don't override existing variables

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | #5568

When extracting the request attributes, existing variables must not be
overridden so that the `$request` variable is passed to the template as
is.

Commits
-------

4b23fdc don't override existing variables

create_framework/templating.rst

@@ -41,7 +41,7 @@ rendered::
 
     function render_template($request)
     {
-        extract($request->attributes->all());
+        extract($request->attributes->all(), EXTR_SKIP);
         ob_start();
         include sprintf(__DIR__.'/../src/pages/%s.php', $_route);
 
@@ -110,7 +110,7 @@ Here is the updated and improved version of our framework::
 
     function render_template($request)
     {
-        extract($request->attributes->all());
+        extract($request->attributes->all(), EXTR_SKIP);
         ob_start();
         include sprintf(__DIR__.'/../src/pages/%s.php', $_route);