[master] 5fb3b4036 need stddef.h for size_t

[Nils Goroll]

commit 5fb3b40362385aeaf75c54dcda4f494af0085d62
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Wed Dec 9 18:07:39 2020 +0100

    need stddef.h for size_t
    
    Ref 001485e6705976bd1029279cb639a394c4dee59c

diff --git a/include/vas.h b/include/vas.h
index 32a092241..ca93fbf43 100644
--- a/include/vas.h
+++ b/include/vas.h
@@ -42,6 +42,7 @@
 
 
 #include <errno.h>
+#include <stddef.h>	// size_t
 
 const char * vstrerror(int e);