Removed hardcoded theme sample hero image. This will allow the user to "blank" out the hero default set in the config. The if statement for blank was unreachable. (#133)

layouts/partials/site-header.html

@@ -1,4 +1,4 @@
-{{ $featured_image := .Param "featured_image" | default "images/gohugo-default-sample-hero-image.jpg" }}
+{{ $featured_image := .Param "featured_image"}}
 {{ if $featured_image }}
   {{/* Trimming the slash and adding absURL make sure the image works no matter where our site lives */}}
   {{ $featured_image := (trim $featured_image "/") | absURL }}