Fix issue with deprecation of ius-release.rpm redirect links

During the gerrit docker build we are installing ius-release.rpm.
According to https://github.com/iusrepo/announce/issues/18 download url
have changed

Change-Id: I2fe19c16a6011da9ff9c2a2f9aca7d59bcd93b78
diff --git a/gerrit/Dockerfile b/gerrit/Dockerfile
index 7618551..5586696 100644
--- a/gerrit/Dockerfile
+++ b/gerrit/Dockerfile
@@ -2,7 +2,7 @@
 
 USER root
 
-RUN yum install -y https://centos7.iuscommunity.org/ius-release.rpm \
+RUN yum install -y https://repo.ius.io/ius-release-el7.rpm \
     && yum install -y python36u python36u-libs python36u-devel python36u-pip
 
 COPY --chown=gerrit:gerrit ssh-config /var/gerrit/.ssh/config