test/docker: adapt packages to CentOS 8

Change-Id: Ied6da85c8e76909ec09a960335bf2327adb1fdd4

src/test/docker/gerrit/Dockerfile

diff --git a/src/test/docker/gerrit/Dockerfile b/src/test/docker/gerrit/Dockerfile
index 5997e7d..3c74b10 100644
--- a/src/test/docker/gerrit/Dockerfile
+++ b/src/test/docker/gerrit/Dockerfile
@@ -6,7 +6,7 @@
 
 USER root
 
-RUN yum install -y iputils-ping netcat curl lsof gettext moreutils net-tools netcat inetutils-ping sudo
+RUN yum install -y iputils nmap curl lsof gettext net-tools sudo
 
 USER gerrit