* mu4e-compose.el: cleanup signature insertion a bit

emacs/mu4e-compose.el

@@ -535,11 +535,11 @@ Gnus' `message-mode'."
       (dolist (att includes)
 	(mml-attach-file
 	  (plist-get att :file-name) (plist-get att :mime-type))))
-    ;; include the message header if it's set; but not when editing an existing
-    ;; message.
+
+    ;; include the message header (if it's set); but not when editing an
+    ;; existing message.
     (unless (eq compose-type 'edit)
-      (when message-signature
-	(message-insert-signature)))
+      (message-insert-signature))
     
     ;; set compose mode -- so now hooks can run
     (mu4e-compose-mode)