libcurl: security bump to version 7.58.0

libcurl: security bump to version 7.58.0

Fixes CVE-2018-1000007: libcurl might leak authentication data to third
parties.

https://curl.haxx.se/docs/adv_2018-b3bf.html

Fixes CVE-2018-1000005: libcurl contains an out bounds read in code handling
HTTP/2 trailers.

https://curl.haxx.se/docs/adv_2018-824a.html

Update license hash due to copyright year change.

[Peter: also add CVE-2018-1000005 reference]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>