[evolution-ews] Fix addressbook upgrade from pre-SHA1 versions

[David Woodhouse <dwmw2 src gnome org>]

commit 7a104f0714f60064a1d3724f5b2267e8c30c4109
Author: David Woodhouse <David Woodhouse intel com>
Date:   Sun Sep 14 22:58:14 2014 +0100

    Fix addressbook upgrade from pre-SHA1 versions

 src/addressbook/e-book-backend-ews.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/addressbook/e-book-backend-ews.c b/src/addressbook/e-book-backend-ews.c
index b4c1c57..fc14b98 100644
--- a/src/addressbook/e-book-backend-ews.c
+++ b/src/addressbook/e-book-backend-ews.c
@@ -2571,7 +2571,8 @@ ews_replace_gal_in_db (EBookBackendEws *cbews,
                        g_slist_free_1 (l);
 
                        g_hash_table_insert (data.uids, search_data->uid, search_data->extra);
-                       g_hash_table_insert (data.sha1s, search_data->extra, search_data->uid);
+                       if (search_data->extra)
+                               g_hash_table_insert (data.sha1s, search_data->extra, search_data->uid);
 
                        /* We steal these */
                        search_data->extra = search_data->uid = NULL;