curl: Enable HTTP Strict-Transport-Security (HSTS) for build in CMake

Upstream curl enabled this by default starting in curl 7.77.  We merged
that version of curl in commit cd40922edb (Merge branch 'upstream-curl'
into update-curl, 2021-05-27, v3.21.0-rc1~120^2~2) but accidentally
switched HSTS off in the build system.  Enable it now.

Utilities/cmcurl/CMakeLists.txt

@@ -25,7 +25,7 @@ set(CURL_DISABLE_FILE OFF CACHE INTERNAL "Disable curl file protocol?")
 set(CURL_DISABLE_FTP OFF CACHE INTERNAL "Disable curl ftp protocol?")
 set(CURL_DISABLE_GETOPTIONS OFF)
 set(CURL_DISABLE_GOPHER ON CACHE INTERNAL "Disable curl gopher protocol?")
-set(CURL_DISABLE_HSTS ON)
+set(CURL_DISABLE_HSTS OFF)
 set(CURL_DISABLE_HTTP_AUTH OFF)
 set(CURL_DISABLE_HTTP OFF CACHE INTERNAL "Disable curl http protocol?")
 set(CURL_DISABLE_IMAP ON CACHE INTERNAL "Disable curl imap protocol?")