Fix memory leaks when adding certificate to store fails

When certificate `cert` exists, but is not added to the store, it causes
memory leaks. The error handling was already existing but the freeing
only happened on the success case.
One could also ponder whether it is necessary to inform the user when
adding a certificate failed or signal this in some way.

Part of the leak report:
```
Direct leak of 384 byte(s) in 1 object(s) allocated from:
    #0 0x7fdbf1f9e9c7 in malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x7fdbf183a7c4 in CRYPTO_zalloc (/lib/x86_64-linux-gnu/libcrypto.so.3+0x2237c4) (BuildId: 0698e1ff610cb3c6993dccbd82c1281b1b4c5ade)
    #2 0x7fdbf16f9d13  (/lib/x86_64-linux-gnu/libcrypto.so.3+0xe2d13) (BuildId: 0698e1ff610cb3c6993dccbd82c1281b1b4c5ade)
    #3 0x7fdbf16f9e19 in ASN1_item_new_ex (/lib/x86_64-linux-gnu/libcrypto.so.3+0xe2e19) (BuildId: 0698e1ff610cb3c6993dccbd82c1281b1b4c5ade)
    #4 0x7fdbf19a59f9 in X509_new_ex (/lib/x86_64-linux-gnu/libcrypto.so.3+0x38e9f9) (BuildId: 0698e1ff610cb3c6993dccbd82c1281b1b4c5ade)
    #5 0x5575bcd295cb in php_openssl_pem_read_bio_x509 /work/php-src/ext/openssl/openssl_backend_v3.c:876
    #6 0x5575bcd2ef3d in php_openssl_load_stream_cafile /work/php-src/ext/openssl/xp_ssl.c:855
    #7 0x5575bcd2f4da in php_openssl_enable_peer_verification /work/php-src/ext/openssl/xp_ssl.c:912
    #8 0x5575bcd33104 in php_openssl_setup_crypto /work/php-src/ext/openssl/xp_ssl.c:1610
    php#9 0x5575bcd39c18 in php_openssl_sockop_set_option /work/php-src/ext/openssl/xp_ssl.c:2512
    php#10 0x5575bdb4c610 in _php_stream_set_option /work/php-src/main/streams/streams.c:1466
    php#11 0x5575bdb5557d in php_stream_xport_crypto_setup /work/php-src/main/streams/transports.c:367
    php#12 0x5575bcd39f11 in php_openssl_sockop_set_option /work/php-src/ext/openssl/xp_ssl.c:2540
    php#13 0x5575bdb4c610 in _php_stream_set_option /work/php-src/main/streams/streams.c:1466
    php#14 0x5575bdb54655 in php_stream_xport_connect /work/php-src/main/streams/transports.c:248
    php#15 0x5575bdb5365d in _php_stream_xport_create /work/php-src/main/streams/transports.c:145
    php#16 0x5575bd8d30b1 in php_stream_url_wrap_http_ex /work/php-src/ext/standard/http_fopen_wrapper.c:490
    php#17 0x5575bd8d857e in php_stream_url_wrap_http /work/php-src/ext/standard/http_fopen_wrapper.c:1204
    php#18 0x5575bdb5073d in _php_stream_open_wrapper_ex /work/php-src/main/streams/streams.c:2270
    php#19 0x5575bd878fa6 in zif_file_get_contents /work/php-src/ext/standard/file.c:409
    php#20 0x5575bd5bfe39 in zif_phar_file_get_contents /work/php-src/ext/phar/func_interceptors.c:226
    php#21 0x5575bdab7ed2 in zend_test_execute_internal /work/php-src/ext/zend_test/observer.c:306
    php#22 0x5575bdde024a in ZEND_DO_FCALL_SPEC_RETVAL_USED_HANDLER /work/php-src/Zend/zend_vm_execute.h:2154
    php#23 0x5575bdf40995 in execute_ex /work/php-src/Zend/zend_vm_execute.h:116519
    php#24 0x5575bdf558b0 in zend_execute /work/php-src/Zend/zend_vm_execute.h:121962
    php#25 0x5575be0ba0ab in zend_execute_script /work/php-src/Zend/zend.c:1980
    php#26 0x5575bdaec8bb in php_execute_script_ex /work/php-src/main/main.c:2645
    php#27 0x5575bdaecccb in php_execute_script /work/php-src/main/main.c:2685
    php#28 0x5575be0bfc16 in do_cli /work/php-src/sapi/cli/php_cli.c:951
    php#29 0x5575be0c21e3 in main /work/php-src/sapi/cli/php_cli.c:1362

... etc ...
```

Closes phpGH-21030.

Author: ndossche

ext/openssl/xp_ssl.c

@@ -859,8 +859,9 @@ static long php_openssl_load_stream_cafile(X509_STORE *cert_store, const char *c
 		buffer_active = 0;
 		if (cert && X509_STORE_add_cert(cert_store, cert)) {
 			++certs_added;
-			X509_free(cert);
 		}
+		/* TODO: notify user when adding certificate failed? */
+		X509_free(cert);
 		goto cert_start;
 	}