Drop HTTPD_CONF and HTTPD_OPTS support from init/sysconfig

Drop HTTPD_CONF and HTTPD_OPTS support from init/sysconfig

HTTPD_CONF support was plain wrong. Seems just copied from Apache
httpd.init and uses a command-line option which is not supported
by nginx. And adds the option to the 'killproc' command too. This
just could not work.

HTTPD_OPTS could work, but was not documented, was named wrong
and seems quite useless (nginx command-line options do not provide
any useful functionality).