Remove only checkstyleConfigDir from configProperties
Remove only checkstyleConfigDir from configProperties

This way custom configuration is still possible

+review REVIEW-6320

lsmaira/gradle,blindpirate/gradle,blindpirate/gradle,gradle/gradle,gstevey/gradle,lsmaira/gradle,blindpirate/gradle,lsmaira/gradle,robinverduijn/gradle,blindpirate/gradle,gstevey/gradle,lsmaira/gradle,blindpirate/gradle,lsmaira/gradle,blindpirate/gradle,gradle/gradle,lsmaira/gradle,lsmaira/gradle,robinverduijn/gradle,gradle/gradle,robinverduijn/gradle,gstevey/gradle,lsmaira/gradle,gstevey/gradle,robinverduijn/gradle,lsmaira/gradle,blindpirate/gradle,blindpirate/gradle,gradle/gradle,gstevey/gradle,robinverduijn/gradle,gstevey/gradle,robinverduijn/gradle,robinverduijn/gradle,gradle/gradle,gradle/gradle,gradle/gradle,gstevey/gradle,gstevey/gradle,robinverduijn/gradle,gradle/gradle,blindpirate/gradle,robinverduijn/gradle,blindpirate/gradle,gradle/gradle,gradle/gradle,robinverduijn/gradle,gstevey/gradle,robinverduijn/gradle,lsmaira/gradle