Remove testing instruction (see bug #5283)
diff --git a/src/thread/pthread/SDL_systhread.c b/src/thread/pthread/SDL_systhread.c
index fb68b24..b892565 100644
--- a/src/thread/pthread/SDL_systhread.c
+++ b/src/thread/pthread/SDL_systhread.c
@@ -41,8 +41,6 @@
#include "../../core/linux/SDL_dbus.h"
#endif /* __LINUX__ */
-#undef HAVE_DLOPEN
-
#if (defined(__LINUX__) || defined(__MACOSX__) || defined(__IPHONEOS__)) && defined(HAVE_DLOPEN)
#include <dlfcn.h>
#ifndef RTLD_DEFAULT