[balsa] meson.build: Use meson's "optimization" option

[Peter Bloomfield <peterb src gnome org>]

commit 77aa5958d35c35892bd9d3e0913b2634c7d13c8c
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Wed Nov 13 17:56:57 2019 -0500

    meson.build: Use meson's "optimization" option
    
    And avoid a warning from ninja.
    
    * meson.build: Use meson's "optimization" option instead of the
      "-O2" compiler flag.

 ChangeLog   | 9 +++++++++
 meson.build | 3 +--
 2 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 5d9cfe979..5d0321612 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2019-11-13  Peter Bloomfield  <pbloomfield bellsouth net>
+
+       meson.build: Use meson's "optimization" option
+
+       And avoid a warning from ninja.
+
+       * meson.build: Use meson's "optimization" option instead of the
+         "-O2" compiler flag.
+
 2019-11-13  Peter Bloomfield  <pbloomfield bellsouth net>
 
        meson.build: Do not enter endless loop
diff --git a/meson.build b/meson.build
index c2ab7e05c..014c418dc 100644
--- a/meson.build
+++ b/meson.build
@@ -1,7 +1,7 @@
 project('balsa', 'c',
         version         : '2.5.9',
         meson_version   : '>= 0.43.0',
-        default_options : 'sysconfdir=/etc')
+        default_options : ['sysconfdir=/etc', 'optimization=2'])
 
 # if meson is used not in a git source tree, use project version:
 balsa_version = meson.project_version()
@@ -512,7 +512,6 @@ if balsa_from_git
     '-Wformat-security',
     '-Wignored-qualifiers',
     '-DGMIME_DISABLE_DEPRECATED',
-    '-O2',
     '-U_FORTIFY_SOURCE',
     '-D_FORTIFY_SOURCE=2',
   ])