[KARAF-1621] Upgrade to maven-site-plugin 3.1
[KARAF-1621] Upgrade to maven-site-plugin 3.1

git-svn-id: 71d8a689455c5fbb0f077bc40adcfc391e14cb9d@1357318 13f79535-47bb-0310-9956-ffa450edef68

grgrzybek/karaf,grgrzybek/karaf,grgrzybek/karaf