Updated code to look for CSRF token in meta tag with name csrf-token

I noticed that after updating to `0.1.2` that the X-CSRF-Token header was still not being correctly sent to my Rails server on POST/DELETE requests with tg-remote. 

Took a look and it appears that it was searching for the csrf meta tag by the wrong name. 
Easy Fix! :)
```
<meta content="Vh9i8xLCMCvBwqMISwXmwmDHgBtR0491vRRg8aazdMz=" name="csrf-token" />
```