gnu: Remove duplicate 'ruby-crass' package.

* gnu/packages/ruby.scm (ruby-crass): Remove duplicate shadowed definition.

gnu/packages/ruby.scm

@@ -1082,24 +1082,6 @@ code in Merb and Rails.")
     (home-page "https://github.com/jnunemaker/crack")
     (license license:expat)))
 
-(define-public ruby-crass
-  (package
-    (name "ruby-crass")
-    (version "1.0.4")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (rubygems-uri "crass" version))
-       (sha256
-        (base32
-         "0bpxzy6gjw9ggjynlxschbfsgmx8lv3zw1azkjvnb8b9i895dqfi"))))
-    (build-system ruby-build-system)
-    (synopsis "Pure Ruby CSS parser based on CSS Syntax Level 3")
-    (description
-     "Crass is a pure Ruby CSS parser based on the CSS Syntax Level 3 spec.")
-    (home-page "https://github.com/rgrove/crass/")
-    (license license:expat)))
-
 (define-public ruby-cliver
   (package
     (name "ruby-cliver")