Merge pull request #1039 from edx/talbs/fix-lms-contentwrapper

edx.org/LMS: FIX - Reverts Sass placeholder extend back to view-based selector

lms/static/sass/multicourse/_account.scss

@@ -97,7 +97,7 @@
   }
 
   // layout
-  %content-wrapper {
+  .content-wrapper {
     background: $account-content-wrapper-bg;
     padding-bottom: 0;
   }