fix #9239 by restoring old ie8 responsive img foo

dist/css/bootstrap.css

@@ -2815,6 +2815,10 @@ button.close {
   background-color: #e5e5e5;
 }
 
+.nav > li > a > img {
+  max-width: none;
+}
+
 .nav-tabs {
   border-bottom: 1px solid #dddddd;
 }

less/navs.less

@@ -60,6 +60,12 @@
   .nav-divider {
     .nav-divider();
   }
+
+  // Prevent IE8 from misplacing imgs
+  // See https://github.com/h5bp/html5-boilerplate/issues/984#issuecomment-3985989
+  > li > a > img {
+    max-width: none;
+  }
 }