md4: include strdup.h for the memdup proto

Reported-by: Erik Schnetter
Fixes #12849
Closes #12863

diff --git a/lib/md4.c b/lib/md4.c
index 067c211e420afdd393b3cdc750c2488fa6590f53..58dd1166cf924f154dc957e0fde3ea637a0b9f0f 100644 (file)
--- a/lib/md4.c
+++ b/lib/md4.c
@@ -28,6 +28,7 @@
 
 #include <string.h>
 
+#include "strdup.h"
 #include "curl_md4.h"
 #include "warnless.h"