Fix home container height (#8284)

* Fix home container height

The home container element's height was not set, so the lower half of
the home component was showing as the wrong color when the user had no
transactions or tokens.

This was broken in #8271, which was a fix for a different CSS problem.
Both problems should remain fixed now with height being set explicitly.

* Remove obsolete `flex` rule

This element is no longer within a flex container as of #8271, so this
rule doesn't do anything.

ui/app/pages/home/index.scss

@@ -1,7 +1,7 @@
 .home {
   &__container {
     display: flex;
-    flex: 1 1 auto;
+    height: 100%;
   }
 
   &__main-view {