memdebug: include `backtrace.h` as system header

Closes #20642

diff --git a/lib/memdebug.c b/lib/memdebug.c
index 457034ebdae2227ed453e777681031b6de84b77f..c4772d3686ba62d79f446204e3907174b4765ac3 100644 (file)
--- a/lib/memdebug.c
+++ b/lib/memdebug.c
@@ -32,7 +32,7 @@
 #include "curlx/fopen.h"  /* for CURLX_FOPEN_LOW(), CURLX_FREOPEN_LOW() */
 
 #ifdef USE_BACKTRACE
-#include "backtrace.h"
+#include <backtrace.h>
 #endif
 
 struct memdebug {