Revert "chatview: remove useless /"

rfc1738 3.10 describes the file URL form: file://<host>/<path>
According to wikipedia, "file://path (i.e. two slashes, without a
hostname) is never correct, but is often used."

This reverts commit 4e6336d8.

Change-Id: Ic3f7c48eb5faa1ec97347328a03c8fda94513faf