Fix a typo in the last commit

In the last commit the automatic-rename option value was saved as yes/no
instead of on/off. While yes/no can work completely fine, it is
different from what is documented in the manual and therefore is not
guaranteed to work on all versions.

scripts/save.sh

@@ -67,7 +67,7 @@ window_format() {
 	format+="${delimiter}"
 	format+="#{window_layout}"
 	format+="${delimiter}"
-	format+="#{?automatic-rename,yes,no}"
+	format+="#{?automatic-rename,on,off}"
 	echo "$format"
 }