[FIX] forums: After html emails are parsed to wiki syntax each new line appears to be doubled up

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52808 b456876b-0849-0410-b77d-98878d47e9d5
[MRG] Automatic merge, branches/13.x 52797 to 52808

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@52809 b456876b-0849-0410-b77d-98878d47e9d5