Fixed a refactoring-related typo (wrong variable name ,issue #27)

Thanks @rancohen2000 for reporting!

Author: Dev-iL

mlapptools.m

@@ -288,7 +288,7 @@ function fontWeight(hUIElement, weight)
           warning(warnState); % Restore warning state
         case {'uipanel', 'figure', 'uitabgroup', 'uitab', ...
           'uiswitch', 'uitoggleswitch', 'uirockerswitch'}
-          widgetID = WidgetID('data-tag', mlapptools.getDataTag(uiElement));
+          widgetID = WidgetID('data-tag', mlapptools.getDataTag(hUIElement));
         case 'uitable'
           TAB_PREFIX = "mgg_";
           % Notes:
@@ -930,4 +930,4 @@ function waitTillWebwindowLoaded(hWin, hUIFig)
 hWin.executeJS('var R = require("react/react-dom.min"); Object.keys(R)')
 
 
-%}
+%}