Remove duplicate rule to generate cert_md5.crt

There were two rules that generated similar files, but with different
dates. Keep the one that's similar to md2 and md4.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index f1c4db8..75b30b5 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -833,10 +833,6 @@
 	cat server1.crt $(test_ca_crt) > $@
 all_final += server1_ca.crt
 
-cert_md5.crt: server1.key
-	$(MBEDTLS_CERT_WRITE) subject_key=server1.key subject_name="C=NL, O=PolarSSL, CN=PolarSSL Cert MD5" serial=6 issuer_crt=$(test_ca_crt) issuer_key=$(test_ca_key_file_rsa) issuer_pwd=$(test_ca_pwd_rsa) not_before=20190210144406 not_after=20290210144406 md=MD5 version=3 output_file=$@
-all_final += cert_md5.crt
-
 cert_sha1.crt: server1.key
 	$(MBEDTLS_CERT_WRITE) subject_key=server1.key subject_name="C=NL, O=PolarSSL, CN=PolarSSL Cert SHA1" serial=7 issuer_crt=$(test_ca_crt) issuer_key=$(test_ca_key_file_rsa) issuer_pwd=$(test_ca_pwd_rsa) not_before=20190210144406 not_after=20290210144406 md=SHA1 version=3 output_file=$@
 all_final += cert_sha1.crt