wks: Fix filter expression syntax flaw.

* tools/wks-util.c (wks_get_key, wks_filter_uid): The filter
expression needs a space before the value.
(install_key_from_spec_file): Replace es_getline by es_read_line and
remove debug output.

A value of starting with '<' was considered an invalid operator due to
our tokenization method.

(cherry picked from commit 0c36ec241d285545f286069843de4f663cd274a3)

• Signed-off-by: Werner Koch <wk@gnupg.org>