Add LC_CTYPE when detecting host_type to deal with UTF-8

The `oo-install` script fails on Fedora 19 because of the Fedora release name (thanks Fedora! :-)

```
irb(main):002:0> s = `cat /etc/redhat-release`
=> "Fedora release 19 (Schr\xC3\xB6dinger\xE2\x80\x99s Cat)\n"
irb(main):003:0> s.match /^Fedora/
ArgumentError: invalid byte sequence in US-ASCII
	from (irb):3:in `match'
	from (irb):3:in `match'
	from (irb):3
	from /usr/bin/irb:12:in `<main>'
irb(main):004:0> 
```
The oo-install failure is:

```
Checking example.com:
/tmp/oo-install-20131118-2143/lib/installer/host_instance.rb:155:in `match': invalid byte sequence in US-ASCII (ArgumentError)
	from /tmp/oo-install-20131118-2143/lib/installer/host_instance.rb:155:in `match'
	from /tmp/oo-install-20131118-2143/lib/installer/host_instance.rb:155:in `host_type
```