rubocop: fix code style

lib/jekyll/tags/highlight.rb

@@ -65,7 +65,7 @@ eos
 
       def parse_options(input)
         options = {}
-        if defined?(input) && input != ""
+        unless input.empty?
           # Split along 3 possible forms -- key="<quoted list>", key=value, or key
           input.scan(/(?:\w="[^"]*"|\w=\w|\w)+/) do |opt|
             key, value = opt.split("=")

lib/jekyll/tags/include.rb

@@ -28,7 +28,7 @@ module Jekyll
           @file = matched["variable"].strip
           @params = matched["params"].strip
         else
-          @file, @params = markup.strip.split(" ", 2)
+          @file, @params = markup.strip.split(/\s+/, 2)
         end
         validate_params if @params
         @tag_name = tag_name