update cs video settings and ohmyzsh

exact_dot_oh-my-zsh/exact_plugins/exact_keychain/keychain.plugin.zsh

@@ -1,7 +1,9 @@
+(( $+commands[keychain] )) || return
+
 # Define SHORT_HOST if not defined (%m = host name up to first .)
 SHORT_HOST=${SHORT_HOST:-${(%):-%m}}
 
-function _start_agent() {
+function {
 	local agents
 	local -a identities
 	local -a options
@@ -28,8 +30,3 @@ function _start_agent() {
 	[ -f "$_keychain_env_sh" ]     && . "$_keychain_env_sh"
 	[ -f "$_keychain_env_sh_gpg" ] && . "$_keychain_env_sh_gpg"
 }
-
-_start_agent
-
-# tidy up after ourselves
-unfunction _start_agent