.tmux.conf: append to terminal-overrides instead of hardcoding index

Author: intelfx

.tmux.conf

@@ -72,7 +72,7 @@ set -g renumber-windows on
 
 # enable OSC 52 support for the built-in selection/clipboard (see below)
 set -g set-clipboard on
-set -g terminal-features[2] "tmux*:clipboard:ccolour:cstyle:focus:title"
+set -ag terminal-features "tmux*:clipboard:ccolour:cstyle:focus:title"
 
 # Rebind select-pane commands to disable key repeat (really annoying)
 bind Up select-pane -U