[pom] Update maven-site-plugin to 3.5.1
[pom] Update maven-site-plugin to 3.5.1

Waffle/waffle,AriSuutariST/waffle,Waffle/waffle,AriSuutariST/waffle,dblock/waffle,AriSuutariST/waffle,hazendaz/waffle,dblock/waffle,AriSuutariST/waffle,dblock/waffle,hazendaz/waffle,hazendaz/waffle,Waffle/waffle,dblock/waffle