Fix varnish syntax, set varnish version to 3.0

Varnish will still fail to start since the local backend is not used anywhere in the config.  This will get you one step closer to working though.

Example of the local backend error:
```
root@drupal-web0:/etc/varnish# /etc/init.d/varnish start
 * Starting HTTP accelerator varnishd                            [fail] 
Message from VCC-compiler:
Unused backend local_5ababd603b, defined:
('input' Line 10 Pos 9)
backend local_5ababd603b {
--------################--

Running VCC-compiler failed, exit 1

VCL compilation failed
```