check.h: remove obsolete header

Since we switched from autotools to Meson in commit
94592c1406, we don't need to include
`config.h` early to properly enable large file support.  Meson passes
the required macros on the compiler command line instead of defining
them in `config.h`.

This means we can include `config.h` at any time, whenever we want to
check its macros, and there are no ordering constraints.

src/lib/curl/Form.cxx

@@ -27,7 +27,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
 #include "Form.hxx"
 
 std::string

src/lib/curl/Global.cxx

@@ -27,7 +27,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
 #include "Global.hxx"
 #include "Request.hxx"
 #include "Log.hxx"
@@ -35,6 +34,7 @@
 #include "event/SocketMonitor.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/Domain.hxx"
+#include "config.h"
 
 static constexpr Domain curlm_domain("curlm");
 

src/lib/curl/Init.cxx

@@ -27,7 +27,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
 #include "Init.hxx"
 #include "Global.hxx"
 #include "event/Call.hxx"

src/lib/curl/Init.hxx

@@ -30,8 +30,6 @@
 #ifndef CURL_INIT_HXX
 #define CURL_INIT_HXX
 
-#include "check.h"
-
 class Mutex;
 class EventLoop;
 class CurlGlobal;