Move VERSION_MKSTRING logic to version.h

Fixes a bug where the VERSION_PATCH define is not yet in scope if
typedefs.h is included before version.h at compilation time.

scene/main/http_request.cpp

@@ -29,6 +29,8 @@
 /*************************************************************************/
 #include "http_request.h"
 
+#include "version.h"
+
 void HTTPRequest::_redirect_request(const String &p_new_url) {
 }