help: strip trailing newline from get_installer_password\n
help: strip trailing newline from get_installer_password\n

ipdb> get_installer_password(opts.dry_run)
'f48BpRGUMSbYjA68nGdQ\n'

Because iterating file object's lines includes them.

LP: #1874009

CanonicalLtd/subiquity,CanonicalLtd/subiquity