[gimp] meson: use "debugoptimized" as the default build type

[Ell <ell src gnome org>]

commit f7c487f53508fc5d4149aa32452884455a1be7c6
Author: Ell <ell_se yahoo com>
Date:   Fri Oct 25 17:24:39 2019 +0300

    meson: use "debugoptimized" as the default build type
    
    ... to match the default autotools behavior.

 meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/meson.build b/meson.build
index 1f007bacdc..8a1109aaf8 100644
--- a/meson.build
+++ b/meson.build
@@ -4,6 +4,7 @@ project('gimp',
   meson_version: '>=0.50.0',
   default_options: [
     'cpp_std=gnu++14',
+    'buildtype=debugoptimized',
   ],
 )