Reference redirectors and jenkins.io as much as possible (#2756)

* Reference redirectors and jenkins.io as much as possible

* Something went wrong, so this is a troubleshooting URL

* More specific redirect URLs

core/src/main/java/hudson/Proc.java

@@ -318,7 +318,7 @@ public abstract class Proc {
 
             try {
                 int r = proc.waitFor();
-                // see http://wiki.jenkins-ci.org/display/JENKINS/Spawning+processes+from+build
+                // see https://jenkins.io/redirect/troubleshooting/process-leaked-file-descriptors
                 // problems like that shows up as infinite wait in join(), which confuses great many users.
                 // So let's do a timed wait here and try to diagnose the problem
                 if (copier!=null)   copier.join(10*1000);
@@ -326,7 +326,7 @@ public abstract class Proc {
                 if((copier!=null && copier.isAlive()) || (copier2!=null && copier2.isAlive())) {
                     // looks like handles are leaking.
                     // closing these handles should terminate the threads.
-                    String msg = "Process leaked file descriptors. See http://wiki.jenkins-ci.org/display/JENKINS/Spawning+processes+from+build for more information";
+                    String msg = "Process leaked file descriptors. See https://jenkins.io/redirect/troubleshooting/process-leaked-file-descriptors for more information";
                     Throwable e = new Exception().fillInStackTrace();
                     LOGGER.log(Level.WARNING,msg,e);
 
@@ -503,7 +503,7 @@ public abstract class Proc {
     /**
     * An instance of {@link Proc}, which has an internal workaround for JENKINS-23271.
     * It presumes that the instance of the object is guaranteed to be used after the {@link Proc#join()} call.
-    * See <a href="https://issues.jenkins-ci.org/browse/JENKINS-23271">JENKINS-23271></a>
+    * See <a href="https://jenkins-ci.org/issue/23271">JENKINS-23271></a>
     * @author Oleg Nenashev
     */
     @Restricted(NoExternalUse.class)