bug #3997 Error handling in case MySQL extension is missing

We can not work with Response object before loading DBI as it uses it.

ChangeLog

@@ -6,6 +6,7 @@ phpMyAdmin - ChangeLog
 - bug Handle the situation where PHP_SELF is not set
 - bug #4080 Overwrite existing file not obeyed
 - bug #3929 Database-specific privileges are not copied when cloning user
+- bug #3997 Error handling in case MySQL extension is missing
 
 4.0.6.0 (2013-09-05)
 - bug #4036 Call to undefined function mb_detect_encoding (clarify the doc)

libraries/common.inc.php

@@ -32,7 +32,7 @@
  */
 
 /**
- * block attempts to directly run this script 
+ * block attempts to directly run this script
  */
 if (getcwd() == dirname(__FILE__)) {
     die('Attack stopped');
@@ -749,11 +749,6 @@ if (@file_exists($_SESSION['PMA_Theme']->getLayoutFile())) {
 }
 
 if (! defined('PMA_MINIMUM_COMMON')) {
-    if (! defined('PMA_BYPASS_GET_INSTANCE')) {
-        // get a dummy object to ensure that the class is instanciated
-        PMA_Response::getInstance();
-    }
-
     /**
      * Character set conversion.
      */