added header hide button class for pre-12.2 minerva

src/js/selections.js

@@ -34,7 +34,7 @@ module.exports = {
     , drugTabInput: '.minerva-drug-panel input.tt-input, #panel_tab_2 input.tt-input'
     , drugTabSearchLink: '.minerva-drug-panel  div[name="searchQuery"] a, #panel_tab_2 div[name="searchQuery"] a'
 
-    ,leftMenuHideButton: '.minerva-header-hide-button'
+    ,leftMenuHideButton: '.minerva-header-hide-button, .headerHideButton'
 
     ,introJsDisableInteractions: 'introjs-disableInteraction'
 };