changed log level to info when if existing header found and skipExistingHeaders is true
Merge branch 'check-skipheaders-reduce-loglevel' of github.com:mlueders/license-gradle-plugin into mlueders-check-skipheaders-reduce-loglevel

Conflicts:
	src/main/groovy/nl/javadude/gradle/plugins/license/maven/LicenseCheckMojo.java