[#7874] Fixed UnicodeEncodeError on ticket attachment diff.
[#7874] Fixed UnicodeEncodeError on ticket attachment diff.

heiths/allura,lym/allura-git,lym/allura-git,apache/allura,heiths/allura,lym/allura-git,apache/allura,lym/allura-git,apache/allura,apache/allura,heiths/allura,heiths/allura,heiths/allura,lym/allura-git,apache/allura