[balsa] meson.build: add -Wignored-qualifiers

[Peter Bloomfield <peterb src gnome org>]

commit 8bbf6ebaa3cbf76b1f68b6bb7cf82d159d2c752f
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Wed Jun 12 19:32:06 2019 -0400

    meson.build: add -Wignored-qualifiers
    
    Add -Wignored-qualifiers to the extra warnings when building from git.

 meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/meson.build b/meson.build
index 774575361..61a257fa9 100644
--- a/meson.build
+++ b/meson.build
@@ -502,6 +502,7 @@ if balsa_from_git
     '-Wredundant-decls',
     '-Wshadow',
     '-Wformat-security',
+    '-Wignored-qualifiers',
     '-DGMIME_DISABLE_DEPRECATED',
     '-O2',
     '-U_FORTIFY_SOURCE',