[Minor] Fix implicit declaration

diff --git a/src/libserver/dkim.c b/src/libserver/dkim.c
index 8b61d39a9bc82f1fa413d126cce593e4e5776117..64226e8b4a238cc48b82387171116bf68a803034 100644 (file)
--- a/src/libserver/dkim.c
+++ b/src/libserver/dkim.c
@@ -22,6 +22,7 @@
 #include "unix-std.h"
 #include "mempool_vars_internal.h"
 
+#include <openssl/err.h>
 #include <openssl/evp.h>
 #include <openssl/rsa.h>
 #include <openssl/engine.h>