nss: remove version selecting dead code

Closes #3262

lib/vtls/nss.c

@@ -1638,17 +1638,6 @@ static CURLcode nss_load_ca_certificates(struct connectdata *conn,
 static CURLcode nss_sslver_from_curl(PRUint16 *nssver, long version)
 {
   switch(version) {
-  case CURL_SSLVERSION_TLSv1:
-    /* TODO: set sslver->max to SSL_LIBRARY_VERSION_TLS_1_3 once stable */
-#ifdef SSL_LIBRARY_VERSION_TLS_1_2
-    *nssver = SSL_LIBRARY_VERSION_TLS_1_2;
-#elif defined SSL_LIBRARY_VERSION_TLS_1_1
-    *nssver = SSL_LIBRARY_VERSION_TLS_1_1;
-#else
-    *nssver = SSL_LIBRARY_VERSION_TLS_1_0;
-#endif
-    return CURLE_OK;
-
   case CURL_SSLVERSION_SSLv2:
     *nssver = SSL_LIBRARY_VERSION_2;
     return CURLE_OK;
@@ -1709,10 +1698,8 @@ static CURLcode nss_init_sslver(SSLVersionRange *sslver,
   }
 
   switch(min) {
-  case CURL_SSLVERSION_DEFAULT:
-    break;
   case CURL_SSLVERSION_TLSv1:
-    sslver->min = SSL_LIBRARY_VERSION_TLS_1_0;
+  case CURL_SSLVERSION_DEFAULT:
     break;
   default:
     result = nss_sslver_from_curl(&sslver->min, min);