ci: install python-rpm-macros for el7

.gitlab-ci.yml

@@ -50,9 +50,10 @@ build:el7:
     - mkdir -p dist/el7
     - yum install -yq
           rpm-build
+          python-rpm-macros
+          python3-rpm-macros
           python-setuptools
           python34-setuptools
-          python3-rpm-macros
   script:
     - python setup.py sdist
     - rpmbuild -tb dist/ligo-common-*.tar.gz