emacs: use --exclude=false when counting total messages

Even if a user excludes a large fraction of their messages, they still
nonetheless exist and are searchable.

emacs/notmuch-hello.el

@@ -785,7 +785,7 @@ Complete list of currently available key bindings:
 		   :help-echo "Refresh"
 		   (notmuch-hello-nice-number
 		    (string-to-number
-		     (car (notmuch--process-lines notmuch-command "count")))))
+		     (car (notmuch--process-lines notmuch-command "count" "--exclude=false")))))
     (widget-insert " messages.\n")))
 
 (defun notmuch-hello-insert-saved-searches ()

test/T440-emacs-hello.sh

@@ -69,7 +69,6 @@ notmuch tag -$tag '*'
 test_expect_equal_file $EXPECTED/notmuch-hello-long-names OUTPUT
 
 test_begin_subtest "All tags show up"
-test_subtest_known_broken
 tag=exclude_me
 notmuch tag +$tag '*'
 notmuch config set search.exclude_tags $tag