[evolution-data-server] CamelHeaderParam: Specify the transfer annotation for camel_header_param

[Corentin Noël <corentinnoel src gnome org>]

commit d10c00a25c3f5c8dd3b0e4985877aa3bd9a96f26
Author: Corentin Noël <corentin noel collabora com>
Date:   Wed Jan 22 12:08:35 2020 +0100

    CamelHeaderParam: Specify the transfer annotation for camel_header_param
    
    This allows us to not change the API to const gchar* yet while preventing possible double-free of the 
returned value.

 src/camel/camel-mime-utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/camel/camel-mime-utils.c b/src/camel/camel-mime-utils.c
index 9e09f386f..3394707e2 100644
--- a/src/camel/camel-mime-utils.c
+++ b/src/camel/camel-mime-utils.c
@@ -2329,7 +2329,7 @@ rfc2184_decode (const gchar *in,
  *
  * Searches @params for a param named @name and gets the value.
  *
- * Returns: the value of the @name param
+ * Returns: (transfer none): the value of the @name param
  **/
 gchar *
 camel_header_param (struct _camel_header_param *params,