bug#45549: Resolving bug with file exists on l10n

[Samuel Klein]

Hello,

I found a minor bug where the script will stop if directory is found.

You can bypass this issue by simply deleting the staging directory and 
re-building. But I submit this patch.

mkdir: cannot create directory ‘l10n’: File exists

starting at line 57

if ! [[ -d l10n ]]; then
  mkdir l10n
fi

Ends on new line 59.

Warm regards,

Samuel Klein