Crashes on startup if config file does not end with a blank line

I tried to modify the folder in which putty looks for the session files, by following the instructions [here](http://jakub.kotrla.net/putty/) and creating a `putty.conf` file. It took me some while to realize that if I didn't end the file with a blank line, putty crashed on startup.

Invalid file: 

```
;Some comment
```

Valid file: 

```
;Some comment

```
