Don't exclude default language from configuration parsing

For some reason the default language (namely EN) was ignored when reading
the configuration file. After discussion with anoe, it appears that
this exclusion happens for historical reasons, so this commit removes it.
4 jobs for improve-conversion-script-interface in 65 minutes and 30 seconds (queued for 3 seconds)
latest
Status Job ID Name Coverage
  Cabal
passed #14964
cabal

00:27:45

 
  Stack
passed #14965
stack

00:04:39

 
  Bench
manual #14966
allowed to fail manual
bench
 
  Test
passed #14967
test

00:33:05