Merge pull request apache#957 from mapr/SPARK-1001-MEP-8.1.0

MapR [SPARK-1001] Update log4j v1 to the 1.3.1-mapr

Author: akhalymon-cv

pom.xml

@@ -121,7 +121,7 @@
     <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
     <sbt.project.name>spark</sbt.project.name>
     <slf4j.version>1.7.30</slf4j.version>
-    <log4j.version>1.3.0-mapr</log4j.version>
+    <log4j.version>1.3.1-mapr</log4j.version>
     <hadoop.version>2.7.6.200-eep-810-SNAPSHOT</hadoop.version>
     <protobuf.version>3.11.1</protobuf.version>
     <yarn.version>${hadoop.version}</yarn.version>