[tracker] configure: Make seccomp support mandatory

[Carlos Garnacho <carlosg src gnome org>]

commit 397e1e00c455babaa1d6e65f04e1f7145020731e
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Dec 8 14:32:10 2016 +0100

    configure: Make seccomp support mandatory
    
    This is something we can do on master, older stable releases will
    have to stick to optional support.

 configure.ac |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index f1a99eb..908777e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2614,6 +2614,8 @@ if test "$have_libseccomp" = "yes"; then
    LIBTRACKER_COMMON_LIBS="$LIBTRACKER_COMMON_LIBS $LIBSECCOMP_LIBS"
    LIBTRACKER_COMMON_CFLAGS="$LIBTRACKER_COMMON_CFLAGS $LIBSECCOMP_CFLAGS"
    AC_DEFINE(HAVE_LIBSECCOMP, [], [Define if we have libseccomp])
+else
+  AC_MSG_ERROR([Libseccomp is mandatory for sandboxed metadata extraction])
 fi
 
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