[balsa/gtk4] Build: Leave out application-helpers

[Peter Bloomfield <peterb src gnome org>]

commit 2671e0693ec3ac271a3c09b438d8e9b9de3b64c1
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Mon Sep 28 14:12:36 2020 -0400

    Build: Leave out application-helpers
    
    They may be irrelevant in gtk4; if not, they need a lot of work!

 libbalsa/meson.build | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/libbalsa/meson.build b/libbalsa/meson.build
index 24c37f76c..c18541c68 100644
--- a/libbalsa/meson.build
+++ b/libbalsa/meson.build
@@ -25,8 +25,9 @@ libbalsa_a_sources = [
   'address-view.h',
   'address.c',
   'address.h',
-  'application-helpers.c',
-  'application-helpers.h',
+  # These might be useful at some point, but for now they are toxic:
+  #'application-helpers.c',
+  #'application-helpers.h',
   'autocrypt.h',
   'autocrypt.c',
   'body.c',