Revert "logging: Use default timeout of 120 seconds for virtlogd"

The same timeout as libvirtd can't be used for virtlogd: even with
socket activation in place, any message produced by QEMU on its
standard output/error between when virtlogd quits due to the timeout
and when it's started again due to socket activation will get lost.

This reverts commit 02b60050Signed-off-by: NAndrea Bolognani <abologna@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/logging/virtlogd.sysconf

 #
 # Pass extra arguments to virtlogd
-VIRTLOGD_ARGS="--timeout 120"
+#VIRTLOGD_ARGS=