[FIXED JENKINS-40362] Upgrads sshd-core to 0.14.0 to pick SSHD-330 (#8)

This solves a really bad issue where 1 handshake
in 256 fails randomly [1].

Note: The issue was easily reproducable, and after this
dependency upgrade the handshake did not fail in over
15K test connections.

[1] https://issues.apache.org/jira/browse/SSHD-330

pom.xml

@@ -52,7 +52,7 @@
     <dependency>
       <groupId>org.apache.sshd</groupId>
       <artifactId>sshd-core</artifactId>
-      <version>0.8.0</version>
+      <version>0.14.0</version>
     </dependency>
     <dependency>
       <groupId>org.jenkins-ci.modules</groupId>

src/main/java/org/jenkinsci/main/modules/sshd/SSHD.java

@@ -23,6 +23,7 @@
 import java.io.IOException;
 import java.security.KeyPair;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -94,10 +95,8 @@ public synchronized void start() throws IOException, InterruptedException {
 
         sshd.setKeyPairProvider(new AbstractKeyPairProvider() {
             @Override
-            protected KeyPair[] loadKeys() {
-                return new KeyPair[] {
-                        new KeyPair(identity.getPublic(),identity.getPrivate())
-                };
+            public Iterable<KeyPair> loadKeys() {
+                return Collections.singletonList(new KeyPair(identity.getPublic(),identity.getPrivate()));
             }
         });