luci-base: fix null error

When working with JSONMap backed data sources in tables, sort
triggers a null error because this.state is not available.
Prevent the null error if it is unavailable.

Signed-off-by: Paul Donald <newtwen+github@gmail.com>

modules/luci-base/htdocs/luci-static/resources/uci.js

@@ -871,7 +871,8 @@ return baseclass.extend(/** @lends LuCI.uci.prototype */ {
 		for (let i = 0; i < sa.length; i++)
 			this.get(conf, sa[i]['.name'])['.index'] = i;
 
-		this.state.reorder[conf] = true;
+		if (this.state)
+			this.state.reorder[conf] = true;
 
 		return true;
 	},