removed support for tmux < 2.4

.tmux.conf.local

@@ -5,16 +5,6 @@
 #         Copyright 2012— Gregory Pakosz (@gpakosz).
 
 
-# -- navigation ----------------------------------------------------------------
-
-# if you're running tmux within iTerm2
-#   - and tmux is 1.9 or 1.9a
-#   - and iTerm2 is configured to let option key act as +Esc
-#   - and iTerm2 is configured to send [1;9A -> [1;9D for option + arrow keys
-# then uncomment the following line to make Meta + arrow keys mapping work
-#set -ga terminal-overrides "*:kUP3=\e[1;9A,*:kDN3=\e[1;9B,*:kRIT3=\e[1;9C,*:kLFT3=\e[1;9D"
-
-
 # -- windows & pane creation ---------------------------------------------------
 
 # new window retains current path, possible values are:
@@ -44,7 +34,7 @@ tmux_conf_new_session_prompt=false
 
 # -- display -------------------------------------------------------------------
 
-# RGB 24-bit colour support (tmux >= 2.2), possible values are:
+# RGB 24-bit colour support, possible values are:
 #  - true
 #  - false
 #  - auto (default)
@@ -96,7 +86,7 @@ tmux_conf_theme_colour_17="#e4e4e4"   # white
 tmux_conf_theme_window_fg="default"
 tmux_conf_theme_window_bg="default"
 
-# highlight focused pane (tmux >= 2.1), possible values are:
+# highlight focused pane, possible values are:
 #   - true
 #   - false (default)
 tmux_conf_theme_highlight_focused_pane=false