Fix sanity test for gating tier0.functional

Add option to disable hostname DNS search during IPA installation.

tests/sanity/runtest.sh

@@ -1,7 +1,7 @@
 #!/bin/sh -eux
 
 systemctl unmask gssproxy
-ipa-server-install --hostname=$(hostname) -r EXAMPLE.TEST -n example.test --setup-dns --no-forwarders --allow-zone-overlap -p Secret123 -a Secret123 -U
+ipa-server-install --hostname=$(hostname) --no-host-dns -r EXAMPLE.TEST -n example.test --setup-dns --no-forwarders --allow-zone-overlap -p Secret123 -a Secret123 -U
 echo Secret123 | kinit admin
 ipa config-show
 ipa-server-install --uninstall -U