HADOOP-19715. Update restrict-imports-enforcer-rule from 2.0.0 to 2.6.1.

Author: slfan1989

pom.xml

@@ -106,7 +106,7 @@ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/x
     <maven-assembly-plugin.version>2.4</maven-assembly-plugin.version>
     <maven-dependency-plugin.version>3.8.1</maven-dependency-plugin.version>
     <maven-enforcer-plugin.version>3.5.0</maven-enforcer-plugin.version>
-    <restrict-imports.enforcer.version>2.0.0</restrict-imports.enforcer.version>
+    <restrict-imports.enforcer.version>2.6.1</restrict-imports.enforcer.version>
     <maven-javadoc-plugin.version>3.0.1</maven-javadoc-plugin.version>
     <maven-gpg-plugin.version>1.5</maven-gpg-plugin.version>
     <maven-remote-resources-plugin.version>1.5</maven-remote-resources-plugin.version>