[evolution] Don't try to convert the 'None' signature

[Tomas Popela <tpopela src gnome org>]

commit 919a8a1107d4c3241fbe34df000a1cc85f740aca
Author: Tomas Popela <tpopela redhat com>
Date:   Wed Aug 17 17:05:30 2016 +0200

    Don't try to convert the 'None' signature

 .../web-extension/e-editor-dom-functions.c         |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/modules/webkit-editor/web-extension/e-editor-dom-functions.c 
b/modules/webkit-editor/web-extension/e-editor-dom-functions.c
index 94d52b2..0a906e2 100644
--- a/modules/webkit-editor/web-extension/e-editor-dom-functions.c
+++ b/modules/webkit-editor/web-extension/e-editor-dom-functions.c
@@ -7027,11 +7027,15 @@ process_node_to_plain_text_changing_composer_mode (EEditorPage *editor_page,
                WEBKIT_DOM_ELEMENT (source), "div.-x-evo-signature-wrapper", NULL);
        if (element) {
                WebKitDOMNode *first_child;
+               gchar *id = NULL;
 
                first_child = webkit_dom_node_get_first_child (WEBKIT_DOM_NODE (element));
+               id = webkit_dom_element_get_id (WEBKIT_DOM_ELEMENT (first_child));
 
-               convert_element_from_html_to_plain_text (
-                       editor_page, WEBKIT_DOM_ELEMENT (first_child), NULL, NULL);
+               if (g_strcmp0 (id, "none") != 0)
+                       convert_element_from_html_to_plain_text (
+                               editor_page, WEBKIT_DOM_ELEMENT (first_child), NULL, NULL);
+               g_free (id);
        }
 }