Update server.xml.erb

if @ssl_port is nil, then Connector tag won't be closed. So closing bracket "/>" should be written outside of "<% if @ssl_port %> ~ <% end %>".
Updates ubuntu DO image
Merge pull request #80 from capriso/patch-1

Fixes issue when SSL is not set.

Obvious Fix Rule Applies.
Merge branch 'master' of github.com:opscode-cookbooks/tomcat
0.16.2 Release