OpenSSL: Fix forcing SSLv3 connections

Since ad34a2d5 (present in 7.34.0 release) forcing
SSLv3 will always return the error "curl: (35) Unsupported SSL protocol
version" Can be replicated with `curl -I -3 https://www.google.com/`.
This fix simply allows for v3 to be forced.

lib/vtls/openssl.c

@@ -1551,6 +1551,7 @@ ossl_connect_step1(struct connectdata *conn,
 
   switch(data->set.ssl.version) {
   case CURL_SSLVERSION_DEFAULT:
+  case CURL_SSLVERSION_SSLv3:
     ctx_options |= SSL_OP_NO_SSLv2;
 #ifdef USE_TLS_SRP
     if(data->set.ssl.authtype == CURL_TLSAUTH_SRP) {