opkg: fix md5 related #ifdef (thx, swalker)

Signed-off-by: Felix Fietkau <[email protected]>

SVN-Revision: 45447

package/system/opkg/patches/230-drop_md5_support.patch

@@ -42,7 +42,7 @@
  
  #include "sprintf_alloc.h"
  #include "file_util.h"
-+#ifdef HAVE_SHA256
++#ifdef HAVE_MD5
  #include "md5.h"
 +#endif
  #include "libbb/libbb.h"