fix(irc): do not emit an error when calling =irc

When the *IRC* workspace is already populated by circe buffers, there is
no reason to emit an error, just switch to the *IRC* workspace and do
nothing.

modules/app/irc/autoload/irc.el

@@ -13,8 +13,7 @@
           (require 'circe)
           (delete-other-windows)
           (switch-to-buffer (doom-fallback-buffer))
-          t)
+          t))))
-      (user-error "IRC buffer is already active and selected"))))
 
 ;;;###autoload
 (defun =irc (&optional inhibit-workspace)