[shotwell] _LIB needs to be a relative dir

[Jens Georg <jensgeorg src gnome org>]

commit b3216719e9504518d6866adaaec532e5a7c09481
Author: Jens Georg <mail jensge org>
Date:   Wed Apr 20 13:49:00 2022 +0200

    _LIB needs to be a relative dir
    
    No idea why that even worked before...
    
    As found by Rico Tzschichholz <ricotz ubuntu com>

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index b8735b5d..25264663 100644
--- a/meson.build
+++ b/meson.build
@@ -12,7 +12,7 @@ conf.set_quoted('_VERSION', meson.project_version())
 conf.set_quoted('_PREFIX', get_option('prefix'))
 conf.set_quoted('_LANG_SUPPORT_DIR', join_paths(get_option('prefix'), get_option('localedir')))
 conf.set_quoted('_LIBEXECDIR', join_paths(get_option('prefix'), get_option('libexecdir')))
-conf.set_quoted('_LIB', join_paths(get_option('prefix'), get_option('libdir')))
+conf.set_quoted('_LIB', get_option('libdir'))
 configure_file(output : 'config.h', configuration: conf)
 
 config_incdir = include_directories('.')