Remove use of deprecated java import from ruby (#449)

* Remove use of deprecated java `import` from ruby

As of jruby-9.3, the use of `import` in ruby file to import java classes
has been deprecated, and the use of `java_import` is recommended.

Relates: jruby/jruby#6976,
         jruby/jruby#7143

Author: robbavey

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 6.3.1
+ - Fix: Removed use of deprecated `import` of java classes in ruby [#449](https://github.com/logstash-plugins/logstash-input-beats/pull/449)
+
 ## 6.3.0
  - Added support for TLSv1.3. [#447](https://github.com/logstash-plugins/logstash-input-beats/pull/447)
 

VERSION

@@ -1 +1 @@
-6.3.0
+6.3.1

lib/logstash/inputs/beats/message_listener.rb

@@ -1,8 +1,8 @@
 # encoding: utf-8
 require "thread_safe"
 require "logstash-input-beats_jars"
-import "javax.net.ssl.SSLPeerUnverifiedException"
-import "org.logstash.beats.MessageListener"
+java_import "javax.net.ssl.SSLPeerUnverifiedException"
+java_import "org.logstash.beats.MessageListener"
 
 module LogStash module Inputs class Beats
   class MessageListener