CHange version

Dockerfile

@@ -37,7 +37,9 @@ ENV LANG en_US.UTF-8
 ENV PATH ${CATALINA_HOME}/bin:${PATH}
 ENV TOMCAT_SOURCE http://archive.apache.org/dist/tomcat
 ENV TOMCAT_WEBAPPS ${CATALINA_HOME}/webapps
-ENV TOMCAT_URL=${TOMCAT_SOURCE}/tomcat-8/v8.5.40/bin/apache-tomcat-8.5.40.tar.gz
+ENV TOMCAT_VERSION=8.5.85
+
+ENV TOMCAT_URL=${TOMCAT_SOURCE}/tomcat-8/v${TOMCAT_VERSION}/bin/apache-tomcat-${TOMCAT_VERSION}.tar.gz
 
 # Install Tomcat
 WORKDIR ${CATALINA_HOME}