mu4e: clear up mu4e~view-message

Remove duplicate definition of mu4e~view-message in mu4e-view-old

Set it earlier in mu4e-view-gnus (so it can be used in mode-hooks).

mu4e/mu4e-view-gnus.el

@@ -59,7 +59,8 @@
     (mm-enable-multibyte)
     (setq
      gnus-summary-buffer (get-buffer-create " *appease-gnus*")
-     gnus-original-article-buffer (current-buffer))
+     gnus-original-article-buffer (current-buffer)
+     mu4e~view-message msg)
     (let* ((ct (mail-fetch-field "Content-Type"))
            (ct (and ct (mail-header-parse-content-type ct)))
            (charset (mail-content-type-get ct 'charset))
@@ -78,7 +79,6 @@
       (mu4e-view-mode)
       (gnus-article-prepare-display))
     (setq mu4e~gnus-article-mime-handles gnus-article-mime-handles)
-    (setq mu4e~view-message msg)
     ;; `mu4e-view-mode' derive from `gnus-article-mode'.
     (mu4e~view-make-urls-clickable)
     (setq gnus-article-decoded-p gnus-article-decode-hook)

mu4e/mu4e-view-old.el

@@ -34,15 +34,6 @@
 
 ;;; Internal variables
 
-;; It's useful to have the current view message available to
-;; `mu4e-view-mode-hooks' functions, and we set up this variable
-;; before calling `mu4e-view-mode'.  However, changing the major mode
-;; clobbers any local variables.  Work around that by declaring the
-;; variable permanent-local.
-(defvar-local mu4e~view-message nil
-  "The message being viewed in view mode.")
-(put 'mu4e~view-message 'permanent-local t)
-
 (defvar mu4e-view-fill-headers t
   "If non-nil, automatically fill the headers when viewing them.")