Fix URIUills.split_file_uri compatibility with newer URI gem

Author: byroot

lib/sprockets/uri_utils.rb

@@ -50,6 +50,9 @@ def split_file_uri(uri)
       # Hack for parsing Windows "file:///C:/Users/IEUser" paths
       path.gsub!(/^\/([a-zA-Z]:)/, '\1'.freeze)
 
+      host = nil if host && host.empty?
+      query = nil if query && query.empty?
+
       [scheme, host, path, query]
     end