[beast] SFI: include numeric for std::iota

[Tim Janik <timj src gnome org>]

commit 0a966c0ca5510a07243a936327d11784ec22a4f7
Author: Tim Janik <timj gnu org>
Date:   Sat Sep 30 15:31:33 2017 +0200

    SFI: include numeric for std::iota
    
    Signed-off-by: Tim Janik <timj gnu org>

 sfi/bcore.hh |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/sfi/bcore.hh b/sfi/bcore.hh
index 51bc939..a68a1dd 100644
--- a/sfi/bcore.hh
+++ b/sfi/bcore.hh
@@ -6,6 +6,7 @@
 #include <sfi/platform.hh>
 #include <sfi/strings.hh>
 #include <sfi/glib-extra.hh>
+#include <numeric>
 #include <algorithm>
 
 namespace Bse {