org-agenda.el: Don't always display a message when removing filters

* lisp/org-agenda.el (org-agenda-filter-remove-all): Only display
a message when called interactively.

lisp/org-agenda.el

@@ -7766,7 +7766,8 @@ which see."
   (when org-agenda-effort-filter
     (org-agenda-filter-show-all-effort))
   (org-agenda-finalize)
-  (message "All agenda filters removed"))
+  (when (called-interactively-p 'interactive)
+    (message "All agenda filters removed")))
 
 (defun org-agenda-filter-by-tag (strip-or-accumulate &optional char exclude)
   "Keep only those lines in the agenda buffer that have a specific tag.