Diminish relative line numbers

It's a little pointless taking up space in the modeline to indicate that
the LR minor mode is active when line numbers are themselves visible
and it is this clear to everyone that they are active.

layers/+distribution/spacemacs/packages-backup.el

@@ -1176,6 +1176,7 @@ on whether the spacemacs-ivy layer is used or not, with
 (defun spacemacs/init-linum-relative ()
   (use-package linum-relative
     :commands (linum-relative-toggle linum-relative-on)
+    :diminish ""
     :init
     (progn
       (when (eq dotspacemacs-line-numbers 'relative)