Fix for 1.8 versions of ruby

lib/gollum/frontend/views/history.rb

@@ -15,8 +15,8 @@ module Precious
             :id7      => v.id[0..6],
             :num      => i,
             :selected => @page.version.id == v.id,
-            :author   => v.author.name.force_encoding('UTF-8'),
+            :author   => v.author.name.respond_to?(:force_encoding) ? v.author.name.force_encoding('UTF-8') : v.author.name,
-            :message  => v.message.force_encoding('UTF-8'),
+            :message  => v.message.respond_to?(:force_encoding) ? v.message.force_encoding('UTF-8') : v.message,
             :date     => v.committed_date.strftime("%B %d, %Y"),
             :gravatar => Digest::MD5.hexdigest(v.author.email) }
         end

lib/gollum/frontend/views/page.rb

@@ -17,7 +17,7 @@ module Precious
         page_versions = @page.versions
         first = page_versions ? page_versions.first : false
         return DEFAULT_AUTHOR unless first
-        first.author.name.force_encoding('UTF-8')
+        first.author.name.respond_to?(:force_encoding) ? first.author.name.force_encoding('UTF-8') : first.author.name
       end
 
       def date