Fix #14 - show installation dialog on 404 page if config not found

404.php

@@ -1,6 +1,11 @@
 <?php 
-require("config.php");
-require("template.php");
+require_once("template.php");
+if (!file_exists("config.php"))
+{
+  require_once("install.php");
+}else{
+require_once("config.php");
+
 Template::render_header("Page not found");
 ?>
   <div class="text-center">
@@ -8,4 +13,5 @@ Template::render_header("Page not found");
     <p><?php echo _("Sorry, but the page you were trying to view does not exist.");?></p>
   </div>
 <?php 
-Template::render_footer();
+Template::render_footer();
+}