[merb-core] Fix Erubis bug causing problems with <%== %>
[merb-core] Fix Erubis bug causing problems with <%== %>

When you used <%== %> to have escaping for HTML you got exception. This
patch fixes behaviour so it's now possible to use <%= %> and <%== %>.

[#1040 state:resolved]

merb/merb-core,merb/merb-core