install mod_ssl on centos 9 stream by default

This change adds mod_ssl to the default set of rpms installed
on rpm based distros.

this is required if the tls-proxy service is enabled
for multi node centos based jobs.

Change-Id: I52652de88352094c824da68e5baf7db4c17cb027
diff --git a/files/rpms/general b/files/rpms/general
index 163a7c8..668705b 100644
--- a/files/rpms/general
+++ b/files/rpms/general
@@ -17,6 +17,7 @@
 libxslt-devel # lxml
 libyaml-devel
 make # dist:openEuler-20.03
+mod_ssl # required for tls-proxy on centos 9 stream computes
 net-tools
 openssh-server
 openssl