[balsa] meson.build: Conditionally define FORTIFY_SOURCE

[Peter Bloomfield <peterb src gnome org>]

commit 42624bfe312cf5be70ea5d01c8fcff3dd9745b58
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Sun Dec 6 18:33:47 2020 -0500

    meson.build: Conditionally define FORTIFY_SOURCE
    
    Define FORTIFY_SOURCE=2 only if the optimiztion level is at least 2.
    See https://gitlab.gnome.org/GNOME/balsa/-/issues/49

 ChangeLog   | 5 +++++
 meson.build | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/ChangeLog b/ChangeLog
index 4d349156c..bdccfd38d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2020-12-06  Peter Bloomfield  <pbloomfield bellsouth net>
+
+       * meson.build: Define the FORTIFY_SOURCE macro only if the
+         optimiztion level is at least 2.
+
 2020-11-01  Peter Bloomfield  <pbloomfield bellsouth net>
 
        main-window: Do not export balsa_window_fix_paned
diff --git a/meson.build b/meson.build
index 7431969cc..08e6fc7da 100644
--- a/meson.build
+++ b/meson.build
@@ -462,7 +462,8 @@ if balsa_from_git
     '-DNM_DISABLE_DEPRECATED',
     '-DPANGO_DISABLE_DEPRECATED',
     ]
-  if get_option('optimization').to_int() >= 2
+  opt_level = get_option('optimization')
+  if opt_level == '2' or opt_level == '3'
     message('Add FORTIFY_SOURCE macro')
     args += [
       '-U_FORTIFY_SOURCE',