Remove unnecessary CSS class nesting

[MAILPOET-2792]

assets/css/src/components-plugin/_premium-page.scss

@@ -30,6 +30,13 @@
     }
   }
 
+  @include breakpoint-max-width(1100px) {
+    h2 {
+      font-size: 2em; // The text WooCommerce is too long and so on smaller displays it overflows. This helps.
+    }
+  }
+}
+
 .mailpoet-premium-page-intro {
   display: flex;
   flex-direction: row;
@@ -153,10 +160,3 @@
 .mailpoet-premium-page-options-divider {
   flex-grow: 100;
 }
-
-  @include breakpoint-max-width(1100px) {
-    h2 {
-      font-size: 2em; // The text WooCommerce is too long and so on smaller displays it overflows. This helps.
-    }
-  }
-}