Fix typo in #3601

plugins/tiddlywiki/katex/wrapper.js

@@ -13,7 +13,7 @@ Wrapper for `katex.min.js` that provides a `<$latex>` widget. It is also availab
 "use strict";
 
 var katex = require("$:/plugins/tiddlywiki/katex/katex.min.js"),
-    parseChem = require("$:/plugins/tiddlywiki/katex/mhchem.min.js"),
+    chemParse = require("$:/plugins/tiddlywiki/katex/mhchem.min.js"),
 	Widget = require("$:/core/modules/widgets/widget.js").widget;
 // Add \ce, \pu, and \tripledash to the KaTeX macros.
 katex.__defineMacro("\\ce", function(context) {