Python: Fix filenames in qhelp

Author: RasmusWL

python/ql/src/experimental/CWE-074/TemplateInjection.qhelp

@@ -13,10 +13,10 @@
     </recommendation>
     <example>
         <p>Consider the example given below, an untrusted HTTP parameter `template` is used to generate a Jinja2 template string. This can lead to remote code execution. </p>
-        <sample src="jinjaBad.py" />
+        <sample src="JinjaBad.py" />
 
         <p>Here we have fixed the problem by using the Jinja sandbox environment for evaluating untrusted code.</p>
-        <sample src="jinjaGood.py" />
+        <sample src="JinjaGood.py" />
     </example>
     <references>
         <li>Portswigger : [Server Side Template Injection](https://portswigger.net/web-security/server-side-template-injection)</li>