use ctrl+a for quick pane switching, not to clash with nested tmux ct…

…rl+a a

.tmux.conf

@@ -37,8 +37,7 @@ setw -g aggressive-resize on
 setw -g xterm-keys on
 
 # quick pane cycling
-unbind ^A
-bind ^A select-pane -t :.+
+bind-key C-a select-pane -t :.+
 
 # window title
 set-option -g set-titles on