[file-roller] do not update if the progress dialog is null

[Paolo Bacchilega <paobac src gnome org>]

commit be63c259099367a73332be59b5bcee4d0c6519f1
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Tue Jun 19 08:16:51 2012 +0200

    do not update if the progress dialog is null

 src/fr-window.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/fr-window.c b/src/fr-window.c
index 32f9ac5..13b24a3 100644
--- a/src/fr-window.c
+++ b/src/fr-window.c
@@ -2362,6 +2362,9 @@ progress_dialog_update_action_description (FrWindow *window)
 	char       *description;
 	char       *description_markup;
 
+	if (window->priv->progress_dialog == NULL)
+		return;
+
 	if (window->priv->convert_data.converting)
 		current_archive = window->priv->convert_data.new_file;
 	else if (window->priv->working_archive != NULL)