now running updates only when using tmux without arguments

fish/functions/tmux.fish

@@ -1,4 +1,5 @@
 function tmux
+  if test (count $argv) -eq 0
     if type -q omf
       # Update Oh My Fish if it installed
       omf update
@@ -20,7 +21,8 @@ function tmux
       # Clean plugins that are not used anymore
       ~/.tmux/plugins/tpm/bin/update_plugins all
     end
+  end
 
   # Execute TMUX
-  /usr/bin/tmux
+  /usr/bin/tmux $argv
 end