hgwebdir: break templater -> templater circular reference
This is essentially another instance of the same problem fixed
by the parent changeset. See its commit message for the details.
#!/bin/sh
mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m test -d "1000000 0"
hg history
hg manifest --debug
hg cat a
hg verify