Revert "Corrected & to & in URL for internalmedia (Fixes #3438)."

This reverts commit e7f95427.

This was causing problems for some media players; see bug #638751

htdocs/artefact/file/blocktype/internalmedia/lib.php

@@ -420,7 +420,7 @@ class PluginBlocktypeInternalmedia extends PluginBlocktype {
 
     private static function get_download_link(ArtefactTypeFile $artefact, BlockInstance $instance, $wmp=false) {
         return get_config('wwwroot') . 'artefact/file/download.php?file=' 
-            . $artefact->get('id') . '&view=' . $instance->get('view')
+            . $artefact->get('id') . '&view=' . $instance->get('view')
             . ($wmp ? '&download=1' : '');
     }