[pom] Update nexus-staging-maven-plugin to 1.6.7
[pom] Update nexus-staging-maven-plugin to 1.6.7

revelc/formatter-maven-plugin,ctubbsii/formatter-maven-plugin,ctubbsii/formatter-maven-plugin,hazendaz/formatter-maven-plugin,revelc/formatter-maven-plugin,hazendaz/formatter-maven-plugin,ctubbsii/formatter-maven-plugin,revelc/formatter-maven-plugin,ctubbsii/formatter-maven-plugin,hazendaz/formatter-maven-plugin,hazendaz/formatter-maven-plugin,revelc/formatter-maven-plugin