Backported Martin D's patch to get rid of adodb debug if feedback off in execute_sql to help with trying to fix up the bad constraint in quiz module for postgres

lib/datalib.php

@@ -21,8 +21,16 @@ function execute_sql($command, $feedback=true) {
 
     global $db;
 
+    $olddebug = $db->debug;
+
+    if (!$feedback) {
+        $db->debug = false;
+    }
+
     $result = $db->Execute("$command");
 
+    $db->debug = $olddebug;
+
     if ($result) {
         if ($feedback) {
             echo "<P><FONT COLOR=green><B>".get_string("success")."</B></FONT></P>";