Remove redundant transform

Author: danieleds

addon/show-invisibles/show-invisibles.js

@@ -90,8 +90,6 @@
                 'position: relative;',
                 'width: 0;',
                 'left: calc(50% - 0.5ch);',
-                'transform: translate(-50%, 0);',
-                '-webkit-transform: translate(-50%, 0);',
                 '}'].join('');
             addStyle(cm, css, 'js-show-tab');
         }