Fix #1707 move substr() outside of get_current_location()

As the title says.

https://github.com/mybb/mybb/issues/1707
I think
```php
if(strlen($location) > 150)
{
	$location = substr($location, 0, 150);
}
```
is same as
```php
$location = substr($location, 0, 150);
```