Add support for empty value config lines

[cosmingrz]

Actually Spamassassin supports empty value config lines for the following type of configs:

<config_name> <list>
<config_name> <boolean>
<config_name> <number>

The default behaviour for this type of config in Spamassassin is ignore line and use the default value

I have started this issue because SpamPAD only supports empty config lines for the first two and for the third is giving a parsing error.

For example:

• If i have this is config file (as you can see freemail_max_body_freemails has no value):

loadplugin Mail::SpamAssassin::Plugin::Check
loadplugin Mail::SpamAssassin::Plugin::FreeMail

report SCORE
report TESTS

freemail_domains example.com
freemail_max_body_freemails

header CHECK_FREEMAIL_BODY eval:check_freemail_body()

util_rb_tld com

• And if i have this in the email:

From: [email protected]

Body contains [email protected] [email protected] [email protected]

Spamassassin ignore the freemail_max_body_freemails line and uses the default value for it so the result is that CHECK_FREEMAIL_BODY rule don't match.

SpamPAD is giving a parsing error with this configuration

pad.errors.PluginError: Invalid value for freemail_max_body_freemails:
ValueError: invalid literal for int() with base 10: ''