Make all SSL checks against boolean values

The method definitions all use boolean values for `ssl` and `ssl_only`. 

```
define nginx::resource::vhost(
 ...
  $ssl                    = false,
```
```
define nginx::resource::location(
...
  $ssl                  = false,
  $ssl_only		= false,
```
But the conditionals inside the manifests are looking for true/false strings. Needless to say this doesn't work and results in SSL configuration not being applied when it should.