remote: remove obsolete params from sysconf file

The LIBVIRTD_CONFIG and LIBVIRTD_NOFILES_LIMIT parameters were only
honoured when using the sysvinit scripts. This was removed already in

    commit 912fe2df
    Author: Andrea Bolognani <abologna@redhat.com>
    Date:   Fri Mar 15 16:47:27 2019 +0100

      Drop support for "Red Hat" init scripts

so the parameters can safely be dropped.
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

src/remote/libvirtd.sysconf

-# Override the default config file
-# NOTE: This setting is no longer honoured if using
-# systemd. Set '--config /etc/libvirt/libvirtd.conf'
-# in LIBVIRTD_ARGS instead.
-#LIBVIRTD_CONFIG=/etc/libvirt/libvirtd.conf
+# Customizations for the libvirtd.service systemd unit
 
 # Listen for TCP/IP connections
 # NB. must setup TLS/SSL keys prior to using this
@@ -19,15 +15,3 @@
 #QEMU_AUDIO_DRV=sdl
 #
 #SDL_AUDIODRIVER=pulse
-
-# Override the maximum number of opened files.
-# This only works with traditional init scripts.
-# In the systemd world, the limit can only be changed by overriding
-# LimitNOFILE for libvirtd.service. To do that, just create a *.conf
-# file in /etc/systemd/system/libvirtd.service.d/ (for example
-# /etc/systemd/system/libvirtd.service.d/openfiles.conf) and write
-# the following two lines in it:
-#   [Service]
-#   LimitNOFILE=2048
-#
-#LIBVIRTD_NOFILES_LIMIT=2048