RPM packager: install python-configparser after "pip install"

Otherwise, "pip install" fails.

docker/packager/rpm/Dockerfile

@@ -2,8 +2,9 @@ FROM centos:centos7
 MAINTAINER BIND 9 Developers <bind9-dev@isc.org>
 RUN yum -y upgrade
 RUN yum -y install epel-release
-RUN yum -y install git iproute jq make mock python-configparser python-pip
+RUN yum -y install git iproute jq make mock python-pip
 RUN pip install cloudsmith-cli
+RUN yum -y install python-configparser
 RUN sed -i '/^\[main\]$/aip_resolve=4' /etc/yum.conf /etc/mock/epel-{6,7,8}-x86_64.cfg
 RUN sed -i 's/\(ip_resolve = CaselessSelectionOption(\)/\1default="ipv4",/' /usr/lib/python2.7/site-packages/yum/config.py
 COPY cloudsmith-isc-bind-dev.repo /etc/yum.repos.d/