Put up a warning and don't accept movie files if we don't have ffmpeg.

This fixes ticket #973.

modules/gallery/libraries/Form_Uploadify.php

@@ -46,6 +46,8 @@ class Form_Uploadify_Core extends Form_Input {
     $v->album = $this->data["album"];
     $v->script_data = $this->data["script_data"];
     $v->simultaneous_upload_limit = module::get_var("gallery", "simultaneous_upload_limit");
+    $v->movies_allowed = (bool) movie::find_ffmpeg();
+    $v->suhosin_session_encrypt = (bool) ini_get("suhosin.session.encrypt");
     return $v;
   }