Merge pull request #861 from apache/dependabot/maven/org.apache.tomcat-tomcat-juli-10.0.21

Bump tomcat-juli from 10.0.16 to 10.0.21

Author: jvz

log4j-appserver/pom.xml

@@ -34,7 +34,7 @@
     <log4jParentDir>${basedir}/..</log4jParentDir>
     <docLabel>Web Documentation</docLabel>
     <projectDir>/log4j-appserver</projectDir>
-    <tomcat-juli.version>10.0.16</tomcat-juli.version>
+    <tomcat-juli.version>10.0.21</tomcat-juli.version>
     <jetty.version>8.2.0.v20160908</jetty.version> <!--  Jetty 9 requires Java 8 -->
     <module.name>org.apache.logging.log4j.appserver</module.name>
     <maven.doap.skip>true</maven.doap.skip>