curl: Fix curl.h inclusion of curlbuild.h from CMake sources

Use a CMake-specific path to this configured header so that it works
when included from a CMake source file in addition to curl sources.
We do not install the Curl headers with CMake, so this hack is okay.

Utilities/cmcurl/include/curl/curl.h

@@ -31,7 +31,7 @@
  */
 
 #include "curlver.h"         /* libcurl version defines   */
-#include "curlbuild.h"       /* libcurl build definitions */
+#include "cmcurl/include/curl/curlbuild.h" /* libcurl build definitions */
 #include "curlrules.h"       /* libcurl rules enforcement */
 
 /*