More cluster menu fixes (#815)

Signed-off-by: Alex Andreev <alex.andreev.email@gmail.com>

src/renderer/components/cluster-icon/cluster-icon.scss

@@ -4,7 +4,6 @@
   position: relative;
   border-radius: $radius;
   padding: $radius;
-  margin-bottom: $padding * 2;
   user-select: none;
   cursor: pointer;
 

src/renderer/components/cluster-manager/clusters-menu.scss

@@ -16,10 +16,10 @@
   .clusters {
     @include hidden-scrollbar;
     padding: 0 $spacing; // extra spacing for cluster-icon's badge
-    margin-bottom: $spacing;
+    margin-bottom: $margin;
 
-    > :last-child {
-      margin-bottom: $margin;
+    .ClusterIcon {
+      margin-bottom: $margin * 1.5;
     }
 
     &:empty {