[balsa/gtk3] Build with threads disabled

[Peter Bloomfield <PeterB src gnome org>]

commit 06b375f3ef206dd1aad0984f29010017dd590601
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Thu Feb 28 08:11:32 2013 -0500

    Build with threads disabled
    
        * libbalsa/mailbox.c: build with threads disabled.

 ChangeLog          |    4 ++++
 libbalsa/mailbox.c |    2 ++
 2 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 8f257d8..9a9322a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2013-02-28  Peter Bloomfield
+
+       * libbalsa/mailbox.c: build with threads disabled.
+
 2013-02-27  Peter Bloomfield
 
        * libbalsa/mailbox.c (lbm_run_filters_on_reception_idle_cb),
diff --git a/libbalsa/mailbox.c b/libbalsa/mailbox.c
index b67cedc..a3c7d75 100644
--- a/libbalsa/mailbox.c
+++ b/libbalsa/mailbox.c
@@ -1216,6 +1216,7 @@ lbm_msgno_changed_expunged_cb(LibBalsaMailbox * mailbox, guint seqno)
     lbm_update_msgnos(mailbox, seqno, mailbox->msgnos_changed);
     pthread_mutex_unlock(&msgnos_changed_lock);
 }
+#endif /* BALSA_USE_THREADS */
 
 static void
 lbm_msgno_row_changed(LibBalsaMailbox * mailbox, guint msgno,
@@ -1237,6 +1238,7 @@ lbm_msgno_row_changed(LibBalsaMailbox * mailbox, guint msgno,
     }
 }
 
+#ifdef BALSA_USE_THREADS
 static gboolean
 lbm_msgnos_changed_idle_cb(LibBalsaMailbox * mailbox)
 {