Fix hostname verification successful test case

The capture of the hostname command would add a \n at the end of the
line and the hostname resolution would fail.

References #384

(cherry picked from commit b8197cc)

Author: acogoluegnes

src/test/java/com/rabbitmq/client/test/ssl/HostnameVerification.java

@@ -111,13 +111,14 @@ public void hostnameVerificationFailsBecauseCertificateNotIssuedForLoopbackInter
         fail("The server certificate isn't issued for 127.0.0.1, the TLS handshake should have failed");
     }
 
+    @Test
     public void hostnameVerificationSucceeds() throws Exception {
         ConnectionFactory connectionFactory = TestUtils.connectionFactory();
         connectionFactory.useSslProtocol(sslContext);
         customizer.accept(connectionFactory);
-        Connection conn = connectionFactory.newConnection(
-            () -> singletonList(new Address(Host.systemHostname(), ConnectionFactory.DEFAULT_AMQP_OVER_SSL_PORT)));
-        assertTrue(conn.isOpen());
-        conn.close();
+        try (Connection conn = connectionFactory.newConnection(
+            () -> singletonList(new Address(Host.systemHostname(), ConnectionFactory.DEFAULT_AMQP_OVER_SSL_PORT)))) {
+            assertTrue(conn.isOpen());
+        }
     }
 }

src/test/java/com/rabbitmq/tools/Host.java

@@ -122,7 +122,7 @@ public static Process invokeMakeTarget(String command) throws IOException {
 
     public static String systemHostname() throws IOException {
         Process process = executeCommandIgnoringErrors("hostname");
-        return capture(process.getInputStream());
+        return capture(process.getInputStream()).trim();
     }
 
     public static String makeCommand()