apache.pom 13 contained m-release-p 2.3.2 with scm 1.7
apache.pom 14 contains m-release-p 2.4.2 with scm 1.7
since scm 1.9 hasn't proven itself enough yet, let's stay on 1.7

git-svn-id: https://svn.apache.org/repos/asf/maven/pom/trunk@1564460 13f79535-47bb-0310-9956-ffa450edef68