Update Nginx redirect target field to show an example placeholder

nginx/lang/en

@@ -326,7 +326,8 @@ rewrite_efrom=Source path $1 contains spaces
 rewrite_eto=Destination URL $1 is missing or contains spaces
 opt_return=Redirect all requests
 rewrite_return_none=No redirect
-rewrite_return_to=to URL
+rewrite_return_to=to
+rewrite_return_eg=/uri or https://example.com$request_uri
 rewrite_return_301=301 (Moved permanently)
 rewrite_return_302=302 (Found)
 rewrite_return_303=303 (See other)

nginx/nginx-lib.pl

@@ -1502,7 +1502,9 @@ my $sel = &ui_select($name."_code", $code || 301,
 return &ui_table_row($text{'opt_'.$name},
 	&ui_opt_textbox($name, $url, 50, $text{'rewrite_return_none'},
 			$sel." ".$text{'rewrite_return_to'}." ", 0,
-			[ $name."_code" ]), 3);
+			[ $name."_code" ], undef,
+			"placeholder=\"".
+			  &quote_escape($text{'rewrite_return_eg'})."\""), 3);
 }
 
 # nginx_return_parse(name, &parent, &in)