Locale issues when building fs

[TechSupportJosh]

Describe the bug
When building the filesystem, we get lots of warnings from perl about locale issues. There's likely a file or command we need to create with locale information.

 
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
	LANGUAGE = "en_GB:en",
	LC_ALL = (unset),
	LC_TIME = "en_GB.UTF-8",
	LC_MONETARY = "en_GB.UTF-8",
	LC_ADDRESS = "en_GB.UTF-8",
	LC_TELEPHONE = "en_GB.UTF-8",
	LC_NAME = "en_GB.UTF-8",
	LC_MEASUREMENT = "en_GB.UTF-8",
	LC_IDENTIFICATION = "en_GB.UTF-8",
	LC_NUMERIC = "en_GB.UTF-8",
	LC_PAPER = "en_GB.UTF-8",
	LANG = "en_GB.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
Extracting templates from packages: 100%

[EdOverflow]

This indicates that you have not set any locales on the machine. In other words, /etc/default/locale does not exist. The Netkit build script should generate locale using locale-gen and then run update-locale to create /etc/default/locale.