Skip IP fallback if harden enabled

app/src/main/java/eu/faircode/email/EmailService.java

@@ -1019,6 +1019,7 @@ public class EmailService implements AutoCloseable {
                                 return;
 
                             // Fallback: check server/certificate IP address
+                            if (!harden)
                                 try {
                                     InetAddress ip = InetAddress.getByName(server);
                                     for (String name : names) {