Reset OpenSSL dependent variables

There is a problem if a TLSv1.3-only server is tested using the OpenSSL 1.0.2-chacha binary and $OSSL_SHORTCUT is true.

$HAS_NO_SSL2 is set to true when find_openssl_binary() is called with OpenSSL 1.0.2-chacha. /usr/bin/openssl does not have the -no_ssl2 option, but the second call to find_openssl_binary(), after setting $OPENSSL to /usr/bin/openssl, does not set $HAS_NO_SSL2 to false. So, later calls to $OPENSSL s_client include the -no_ssl2 option, resulting in connection failures.

This PR fixes the problem by modifying find_openssl_binary() to ensure that every OpenSSL-dependent variable is set by this function.

testssl.sh

@@ -16597,6 +16597,35 @@ find_openssl_binary() {
          OPENSSL_LOCATION="$openssl_location"
      fi
 
+     OSSL_CIPHERS_S=""
+     HAS_SSL2=false
+     HAS_SSL3=false
+     HAS_TLS13=false
+     HAS_X448=false
+     HAS_X25519=false
+     HAS_NO_SSL2=false
+     HAS_NOSERVERNAME=false
+     HAS_CIPHERSUITES=false
+     HAS_COMP=false
+     HAS_NO_COMP=false
+     OSSL_SUPPORTED_CURVES=""
+     HAS_PKEY=false
+     HAS_PKUTIL=false
+     HAS_ALPN=false
+     HAS_NPN=false
+     HAS_FALLBACK_SCSV=false
+     HAS_PROXY=false
+     HAS_XMPP=false
+     HAS_POSTGRES=false
+     HAS_MYSQL=false
+     HAS_LMTP=false
+     HAS_NNTP=false
+     HAS_IRC=false
+     HAS_CHACHA20=false
+     HAS_AES128_GCM=false
+     HAS_AES256_GCM=false
+     HAS_ZLIB=false
+     
      $OPENSSL ciphers -s 2>&1 | grep -aq "unknown option" || \
           OSSL_CIPHERS_S="-s"