config2setopts: fix for --disable-aws configuration

[majstar]

Hello.
I noticed that curl binary does not work as intended when built with --disable-aws setting. While using curl for http queries, it kept exiting with the following error:

$ ./curl http://curl.se
curl: (48) An unknown option was passed in to libcurl

The cause of the problem is the usage of MY_SETOPT_STR macro for setting CURLOPT_AWS_SIGV4 in http_setopts() when other AWS-related code is disabled. Adding the corresponding #ifndef macro fixed the problem.

Also result variable in http_setopts() should be preset to CURLE_OK value, because otherwise http_setopts() may return the value of uninitialised variable and the following error will occur:

$ ./curl http://curl.se
curl: (32542) Unknown error

My commit fixes the problem.

[bagder]

Thanks!