[fix] [minor] letterhead max-width as 100% in print format

public/js/legacy/print_format.js

@@ -311,7 +311,8 @@ $.extend(_p, {
 	// Attach letterhead at top of container
 	show_letterhead: function(container, args) {	
 		if(!(args.no_letterhead || args.only_body)) {
-			container.innerHTML = '<div>' + _p.get_letter_head() + '</div>' 
+			container.innerHTML = '<div style="max-width: 100%">' 
+				+ _p.get_letter_head() + '</div>' 
 				+ container.innerHTML;
 		}
 	},