test: generate des rsa_cert.pfx

My node distribution uses a shared openssl library with some ciphers
disabled, including RC2.

These tests (which use `rsa_cert.pfx`) fail with `unknown cipher`:
 - parallel/test-crypto-binary-default
 - parallel/test-https-pfx
 - parallel/test-crypto

The other fixture .pfx's use the `-descert` option, I don't know if
rsa_cert.pfx was generated without `-descert` intentionally or not but
none of the tests reference RC2, and the tests pass with a des cert.

I'm not an ssl/crypto expert, so I would appreciate any insight.

Old key:
```
openssl pkcs12 -info -in test/fixtures/keys/rsa_cert.pfx -noout -passin
pass:sample
MAC Iteration 2048
MAC verified OK
PKCS7 Encrypted data: pbeWithSHA1And40BitRC2-CBC, Iteration 2048
Certificate bag
PKCS7 Data
Shrouded Keybag: pbeWithSHA1And3-KeyTripleDES-CBC, Iteration 2048
```

New
```
openssl pkcs12 -info -in test/fixtures/keys/rsa_cert.pfx -noout -passin
pass:sample
MAC Iteration 2048
MAC verified OK
PKCS7 Encrypted data: pbeWithSHA1And3-KeyTripleDES-CBC, Iteration 2048
Certificate bag
PKCS7 Data
Shrouded Keybag: pbeWithSHA1And3-KeyTripleDES-CBC, Iteration 2048
```

PR-URL: #28471
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Author: everett1992

test/fixtures/keys/Makefile

@@ -631,7 +631,7 @@ rsa_cert.crt: rsa_private.pem
 	openssl req -new -x509 -days 99999 -key rsa_private.pem -config rsa_cert.cnf -out rsa_cert.crt
 
 rsa_cert.pfx: rsa_cert.crt
-	openssl pkcs12 -export -passout 'pass:sample' -inkey rsa_private.pem -in rsa_cert.crt -out rsa_cert.pfx
+	openssl pkcs12 -export -descert -passout 'pass:sample' -inkey rsa_private.pem -in rsa_cert.crt -out rsa_cert.pfx
 
 rsa_ca.crt: rsa_cert.crt
 	cp rsa_cert.crt rsa_ca.crt