Don't bail when setting up horizon on openSUSE

I85325179f1792d985b0375572abfe8c8a82fecc3 accidentally removed the
conditional branch required to prevent setup of horizon aborting on
openSUSE, so put it back in.

Change-Id: Ia3e4464a2d718e402d84a0bcf60f13ef30404969
diff --git a/lib/horizon b/lib/horizon
index 5973eb2..048887e 100644
--- a/lib/horizon
+++ b/lib/horizon
@@ -130,6 +130,8 @@
             HORIZON_REQUIRE='Require all granted'
         fi
         sudo sed '/^Listen/s/^.*$/Listen 0.0.0.0:80/' -i /etc/httpd/conf/httpd.conf
+    elif is_suse; then
+        : # nothing to do
     else
         exit_distro_not_supported "apache configuration"
     fi