Fix. static assert. now only magic field should match

Author: moteus

src/lceasy.c

@@ -1051,9 +1051,8 @@ void lcurl_easy_initlib(lua_State *L, int nup){
   /* Hack. We ensure that lcurl_easy_t and lcurl_hpost_stream_t
      compatiable for readfunction
   */
-  LCURL_STATIC_ASSERT(offsetof(lcurl_easy_t, L)       == offsetof(lcurl_hpost_stream_t, L));
-  LCURL_STATIC_ASSERT(offsetof(lcurl_easy_t, rd)      == offsetof(lcurl_hpost_stream_t, rd));
-  LCURL_STATIC_ASSERT(offsetof(lcurl_easy_t, rbuffer) == offsetof(lcurl_hpost_stream_t, rbuffer));
+  LCURL_STATIC_ASSERT(offsetof(lcurl_easy_t, magic)     == offsetof(lcurl_hpost_stream_t, magic));
+  LCURL_STATIC_ASSERT(sizeof(((lcurl_easy_t*)0)->magic) == sizeof(((lcurl_hpost_stream_t*)0)->magic));
 
   if(!lutil_createmetap(L, LCURL_EASY, lcurl_easy_methods, nup))
     lua_pop(L, nup);