[balsa] address-book-text: Return NULL instead of 0

[Peter Bloomfield <peterb src gnome org>]

commit c9b5daa710bd9c8c869e9319d127b808884fc8c5
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Wed Jun 5 19:51:26 2019 -0400

    address-book-text: Return NULL instead of 0

 libbalsa/address-book-text.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/libbalsa/address-book-text.c b/libbalsa/address-book-text.c
index fab865bd5..07045b56a 100644
--- a/libbalsa/address-book-text.c
+++ b/libbalsa/address-book-text.c
@@ -793,7 +793,7 @@ libbalsa_address_book_text_get_name_complete(LibBalsaAddressBookText * ab_text)
     LibBalsaAddressBookTextPrivate *priv =
         libbalsa_address_book_text_get_instance_private(ab_text);
 
-    g_return_val_if_fail(LIBBALSA_IS_ADDRESS_BOOK_TEXT(ab_text), 0);
+    g_return_val_if_fail(LIBBALSA_IS_ADDRESS_BOOK_TEXT(ab_text), NULL);
 
     return priv->name_complete;
 }