Update certificates to expire in 2029

Update certificates that expire on 2021, to prolong their validity,
to make tests pass three years ahead.
diff --git a/tests/data_files/cert_md5.crt b/tests/data_files/cert_md5.crt
index e514fd6..8b4d089 100644
--- a/tests/data_files/cert_md5.crt
+++ b/tests/data_files/cert_md5.crt
@@ -1,20 +1,20 @@
 -----BEGIN CERTIFICATE-----
 MIIDPzCCAiegAwIBAgIBBjANBgkqhkiG9w0BAQQFADA7MQswCQYDVQQGEwJOTDER
 MA8GA1UECgwIUG9sYXJTU0wxGTAXBgNVBAMMEFBvbGFyU1NMIFRlc3QgQ0EwHhcN
-MDAwMTAxMTIxMjEyWhcNMzAwMTAxMTIxMjEyWjA8MQswCQYDVQQGEwJOTDERMA8G
+MTkwMjEwMTQ0NDA2WhcNMjkwMjEwMTQ0NDA2WjA8MQswCQYDVQQGEwJOTDERMA8G
 A1UECgwIUG9sYXJTU0wxGjAYBgNVBAMMEVBvbGFyU1NMIENlcnQgTUQ1MIIBIjAN
-BgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyHTEzLn5tXnpRdkUYLB9u5Pyax6f
-M60Nj4o8VmXl3ETZzGaFB9X4J7BKNdBjngpuG7fa8H6r7gwQk4ZJGDTzqCrSV/Uu
-1C93KYRhTYJQj6eVSHD1bk2y1RPD0hrt5kPqQhTrdOrA7R/UV06p86jt0uDBMHEw
-MjDV0/YI0FZPRo7yX/k9Z5GIMC5Cst99++UMd//sMcB4j7/Cf8qtbCHWjdmLao5v
-4Jv4EFbMs44TFeY0BGbH7vk2DmqV9gmaBmf0ZXH4yqSxJeD+PIs1BGe64E92hfx/
-/DZrtenNLQNiTrM9AM+vdqBpVoNq0qjU51Bx5rU2BXcFbXvI5MT9TNUhXwIDAQAB
-o00wSzAJBgNVHRMEAjAAMB0GA1UdDgQWBBRxoQBzckAvVHZeM/xSj7zx3WtGITAf
+BgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqQIfPUBq1VVTi/027oJlLhVhXom/
+uOhFkNvuiBZS0/FDUEeWEllkh2v9K+BG+XO+3c+S4ZFb7Wagb4kpeUWA0INq1UFD
+d185fAkER4KwVzlw7aPsFRkeqDMIR8EFQqn9TMO0390GH00QUUBncxMPQPhtgSVf
+CrFTxjB+FTms+Vruf5KepgVb5xOXhbUjktnUJAbVCSWJdQfdphqPPwkZvq1lLGTr
+lZvc/kFeF6babFtpzAK6FCwWJJxK3M3Q91Jnc/EtoCP9fvQxyi1wyokLBNsupk9w
+bp7OvViJ4lNZnm5akmXiiD8MlBmj3eXonZUT7Snbq3AS3FrKaxerUoJUsQIDAQAB
+o00wSzAJBgNVHRMEAjAAMB0GA1UdDgQWBBQfdNY/KcF0dEU7BRIsPai9Q1kCpjAf
 BgNVHSMEGDAWgBS0WuSls97SUva51aaVD+s+vMf9/zANBgkqhkiG9w0BAQQFAAOC
-AQEAF4QcMshVtVbYgvvU7f2lWakubbAISM/k+FW/f7u63m0MSSoSFeYflBOC1Wf4
-imgDEnWcWTH5V7sxsLNogxfpfTuFUaKfHeQmRhAK4UgqbDEs4dZvgo3wZ/w92G0/
-QNntJefnqaFiITXZTn6J8hxeoEq4QbucbWgeY6fTAwXtIv40BvMOSakkuIFAyIvV
-90VY1j4vnx0/xv5lIBAxah1HdtXhqtDu/sUfdCtWX5SCcVUwwM3gZ4Q1ZdWQmlvF
-737ZG7XaINxsDaI04sJxc7qvuRYhLdCwUPnZL5TGEQJ8jNa/39eEbnkvs7hbTU98
-6qG8UAYsSI7aMe1j7DZpkoPL9w==
+AQEAPO/yXYVCQfm1gRzYoPP4T8Dd7jfpS0Yz5hAWMDi73aXufk9ltGdXauQxA4Pu
+NQLWBMFMtJyO2OUb0p+oPGCxQayLx1sIjS9Gfy70xHlL3jnZy4kLXtkiARz8ZptW
+krxzQh017mXIn8W2VGYWA1gCNrg/Xb3VtlxVCzPa2zGCkIJHKe/dqNtKY3xx/SEQ
+gsVvdT8lpI8HfeElBfWvFxGps77pvE2HDcAdrIkjrsBWoSIq6CqIQjyW7WSN7UgI
+bTczqejHkrggI8yWIIoDAiUX9OGT76Mv4wpmOPww8hqoVfpvvPQ2l6byVNJYPj/L
+oiUV6sDYenOgMJ3Tf7UzTR91MA==
 -----END CERTIFICATE-----