HADOOP-15410 (#366)

HADOOP-15410. Update scope of log4j in hadoop-auth to provided. Contributed by lqjacklee.

hadoop-common-project/hadoop-auth/pom.xml

@@ -90,7 +90,7 @@
     <dependency>
       <groupId>log4j</groupId>
       <artifactId>log4j</artifactId>
-      <scope>runtime</scope>
+      <scope>provided</scope>
     </dependency>
     <dependency>
       <groupId>org.slf4j</groupId>