lib: CURLOPT_HAPPY_EYEBALLS_TIMEOUT => CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS

- In keeping with the naming of our other connect timeout options rename
  CURLOPT_HAPPY_EYEBALLS_TIMEOUT to CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS.

This change adds the _MS suffix since the option expects milliseconds.
This is more intuitive for our users since other connect timeout options
that expect milliseconds use _MS such as CURLOPT_TIMEOUT_MS,
CURLOPT_CONNECTTIMEOUT_MS, CURLOPT_ACCEPTTIMEOUT_MS.

The tool option already uses an -ms suffix, --happy-eyeballs-timeout-ms.

Follow-up to 2427d94 which added the lib and tool option yesterday.

Ref: https://github.com/curl/curl/pull/2260

lib/setopt.c

@@ -2533,7 +2533,7 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option,
   case CURLOPT_SSH_COMPRESSION:
     data->set.ssh_compression = (0 != va_arg(param, long))?TRUE:FALSE;
     break;
-  case CURLOPT_HAPPY_EYEBALLS_TIMEOUT:
+  case CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS:
     arg = va_arg(param, long);
     if(arg < 0)
       return CURLE_BAD_FUNCTION_ARGUMENT;