[libgda] Valadoc: fix output for Gda-6.0 documentation

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 80a97fee93fdd7bd289375cebc96be196d904864
Author: Daniel Espinosa <esodan gmail com>
Date:   Tue Aug 14 12:49:18 2018 -0500

    Valadoc: fix output for Gda-6.0 documentation

 doc/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/doc/meson.build b/doc/meson.build
index fe3882747..1721e4757 100644
--- a/doc/meson.build
+++ b/doc/meson.build
@@ -20,7 +20,7 @@ if valadoc.found()
                        '--package-version='+project_version,
                        '--package-name='+'Gda-'+project_api_version,
                        '--doclet=devhelp',
-                       '-o', '@OUTPUT@',
+                       '-o', meson.current_build_dir(),
                        '@INPUT@'
                        ],
                input: libgda_vapi,