emacs: update alist for mail-archive.com API change

Searching by Message-Id no longer works via the old mail-archive.com
API, though I have contacted them in hopes that they restore it to
prevent dead links.  Anyway, the new API is cleaner.

Acked-by: Austin Clements <amdragon@MIT.EDU>

emacs/notmuch-show.el

@@ -171,7 +171,7 @@ each attachment handler is logged in buffers with names beginning
 (defcustom notmuch-show-stash-mlarchive-link-alist
   '(("Gmane" . "http://mid.gmane.org/")
     ("MARC" . "http://marc.info/?i=")
-    ("Mail Archive, The" . "http://mail-archive.com/search?l=mid&q=")
+    ("Mail Archive, The" . "http://mid.mail-archive.com/")
     ("LKML" . "http://lkml.kernel.org/r/")
     ;; FIXME: can these services be searched by `Message-Id' ?
     ;; ("MarkMail" . "http://markmail.org/")

test/T310-emacs.sh

@@ -727,7 +727,7 @@ inbox,stashtest
 ${gen_msg_filename}
 http://mid.gmane.org/bought
 http://marc.info/?i=bought
-http://mail-archive.com/search?l=mid&q=bought
+http://mid.mail-archive.com/bought
 EOF
 test_expect_equal_file OUTPUT EXPECTED