[FIXED JENKINS-8647] Many messages about RecordReaper IllegalArgumentException

I did a checkout for our internal fork of JmDNS [1] and the
upstream version [2] to compare what the differences were..
I found none. There do not appear to be any local edits to
our fork so I can not figure out why we did the fork to
begin with.

Perhaps some older version had locally patched bugs which
have since been resolved? Anyhow, given that JENKINS-8647
is causing lots of people lots of grief, and it is enabled
by default, I went ahead and bumped to jmdns-3.4.0 upstream.

I think reduction of forks for library projects is generally
good, and especially when we have no practical changes made
to our version.

[1] https://github.com/jenkinsci/jmdns
[2] https://jmdns.svn.sourceforge.net/svnroot/jmdns/tags/JmDNS_3_2_1/

core/pom.xml

@@ -738,9 +738,9 @@ THE SOFTWARE.
       <version>3.2.7</version>
     </dependency>
     <dependency>
-      <groupId>org.jvnet.hudson</groupId>
+      <groupId>javax.jmdns</groupId>
       <artifactId>jmdns</artifactId>
-      <version>3.2.1-hudson-1</version>
+      <version>3.4.0</version>
     </dependency>
     <dependency>
       <groupId>com.sun.winsw</groupId>

core/src/main/java/hudson/DNSMultiCast.java

@@ -48,8 +48,12 @@ public class DNSMultiCast implements Closeable {
 
     public void close() {
         if (jmdns!=null) {
-            jmdns.close();
-            jmdns = null;
+            try {
+                jmdns.close();
+                jmdns = null;
+            } catch (final IOException e) {
+                LOGGER.log(Level.WARNING,"Failed to close down JmDNS instance!",e);
+            }
         }
     }