[libgda/LIBGDA_6.0] Fix vapi generation for vala >= 0.54

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 57f618a3b2a3758ee3dcbf9bbdc566122dd8566d
Author: Daniel Espinosa <esodan gmail com>
Date:   Tue Jan 18 10:35:36 2022 -0600

    Fix vapi generation for vala >= 0.54

 libgda/Gda-6.0-custom.vala | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/libgda/Gda-6.0-custom.vala b/libgda/Gda-6.0-custom.vala
index d046c5c24..cf941617a 100644
--- a/libgda/Gda-6.0-custom.vala
+++ b/libgda/Gda-6.0-custom.vala
@@ -89,10 +89,13 @@ namespace Gda {
                public abstract void* _gda_reserved3 ();
                public abstract void* _gda_reserved4 ();
        }
+
+#if VALA_0_54
+#else
        [CCode (cheader_filename = "libgda.h", copy_function = "g_boxed_copy", free_function = 
"g_boxed_free", type_id = "gda_sql_statement_get_type ()")]
        [Compact]
        public class SqlStatement {
                public static Gda.SqlStatementContentsInfo get_contents_infos (Gda.SqlStatementType type);
        }
-
+#endif
 }