Fix for Outgoing Links Warning page being displayed in IE for internal links.

IE appears to set the 'host' property of anchor tags to "" for internal links, this was causing all internal links to be treated as external and therefore being rewritten to point at the Outgoing Link Warning page at /outgoing/
Merge pull request #2216 from kazrudys/v0.5.x

Fix for Outgoing Links Warning page being displayed in IE for internal links