Explicitly set SSL_VERIFY_MODE during start ssl in Client

perl-xCAT/xCAT/Client.pm

@@ -223,6 +223,7 @@ if (ref($request) eq 'HASH') { # the request is an array, not pure XML
     SSL_key_file => $keyfile,
     SSL_cert_file => $certfile,
     SSL_ca_file => $cafile,
+    SSL_verify_mode => SSL_VERIFY_PEER,
     SSL_use_cert => 1,
     Timeout => 0,
    );