fix(mdUtil): fix disable scroll adding extra scroll-bars on IE

closes #5300

Thanks @van88 for the investigation.

Author: rschmukler

src/core/util/util.js

@@ -234,7 +234,7 @@ function UtilFactory($document, $timeout, $compile, $rootScope, $$mdAnimate, $in
         var scrollOffset = $mdUtil.scrollTop(body);
         var clientWidth = body.clientWidth;
 
-        if (body.scrollHeight > body.clientHeight) {
+        if (body.scrollHeight > body.clientHeight + 1) {
           applyStyles(body, {
             position: 'fixed',
             width: '100%',