Improved: Reference the Servlet javadoc from Apache Tomcat (OFBIZ-11300)

Since we are using the servlet API implemented by Apache Tomcat, it is
better to use its documentation than the one from oracle which is not
updated anymore because of Java EE community adoption.

build.gradle

@@ -98,7 +98,7 @@ javadoc {
         // versions declared in the 'dependencies' block.
         links(
             'https://docs.oracle.com/javase/8/docs/api',
-            'https://docs.oracle.com/javaee/7/api',
+            'https://tomcat.apache.org/tomcat-9.0-doc/servletapi/',
             'http://docs.groovy-lang.org/docs/groovy-2.5.8/html/api',
             'https://commons.apache.org/proper/commons-cli/apidocs'
         )
@@ -189,7 +189,7 @@ dependencies {
     implementation 'org.apache.sshd:sshd-core:1.7.0'
     implementation 'org.apache.tika:tika-core:1.22'
     implementation 'org.apache.tika:tika-parsers:1.22'
-    implementation 'org.apache.tomcat:tomcat-catalina-ha:9.0.27'
+    implementation 'org.apache.tomcat:tomcat-catalina-ha:9.0.27' // Remember to change the version number in javadoc.options block
     implementation 'org.apache.tomcat:tomcat-catalina:9.0.27'
     implementation 'org.apache.tomcat:tomcat-jasper:9.0.27'
     implementation 'org.apache.tomcat:tomcat-tribes:9.0.27'