Remove unnecessary mu_message_t flag (MESSAGE_MIME_OWNER)

@@ -32,7 +32,6 @@ extern "C" {
 
 #define MESSAGE_MODIFIED        0x10000
 #define MESSAGE_INTERNAL_STREAM 0x20000
-#define MESSAGE_MIME_OWNER      0x40000
 
 struct _mu_message
 {

@@ -36,9 +36,8 @@ mu_message_is_multipart (mu_message_t msg, int *pmulti)
 	  int status = mu_mime_create (&msg->mime, msg, 0);
 	  if (status != 0)
 	    return 0;
-	  msg->flags |= MESSAGE_MIME_OWNER;
 	}
-      *pmulti = mu_mime_is_multipart(msg->mime);
+      *pmulti = mu_mime_is_multipart (msg->mime);
     }
   return 0;
 }

@@ -1074,7 +1074,6 @@ mu_mime_get_num_parts (mu_mime_t mime, size_t *nmtp_parts)
     }
   *nmtp_parts = mime->nmtp_parts;
   return (ret);
-
 }
 
 int
@@ -1149,7 +1148,6 @@ mu_mime_to_message (mu_mime_t mime, mu_message_t *pmsg)
   if (rc == 0)
     {
       mu_message_unref (msg);
-      msg->flags |= MESSAGE_MIME_OWNER;
       mime->msg = NULL;
       mu_mime_ref (mime);
       *pmsg = msg;