Fix building with --enable-openssl after removed config.h inclusion from
public header files
diff --git a/crypto/rng/rand_source_ossl.c b/crypto/rng/rand_source_ossl.c
index ee836ce..4bca6ac 100644
--- a/crypto/rng/rand_source_ossl.c
+++ b/crypto/rng/rand_source_ossl.c
@@ -42,6 +42,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
 #include "rand_source.h"
 #include <openssl/rand.h>