fix(style): bg-image selector hierarchy

Fixes #1951

wowchemy/assets/scss/wowchemy/_widgets.scss

@@ -70,7 +70,7 @@
 }
 
 /* Default background image properties for home sections. */
-.home-section-bg .bg-image {
+.home-section-bg.bg-image {
   background-position: center;
   background-repeat: no-repeat;
   background-size: cover;