Fix null pointer exception when reporting on SSH server startup failure

Signed-off-by: Shawn O. Pearce <sop@google.com>

appjar/src/main/java/com/google/gerrit/server/ssh/SshServlet.java

@@ -84,7 +84,7 @@ public class SshServlet extends HttpServlet {
       sshd.start();
     } catch (IOException e) {
       sshd = null;
-      throw new ServletException("Cannot start sshd on " + sshd.getPort(), e);
+      throw new ServletException("Cannot start sshd on " + myPort, e);
     }
   }