[vala/0.50] vala: Fix build with valac < 0.44

[Rico Tzschichholz <ricotz src gnome org>]

commit f4757444f9a02a3203e82b0bccbd917812a42140
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Mar 3 17:37:04 2021 +0100

    vala: Fix build with valac < 0.44

 vala/valacodecontext.vala | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/vala/valacodecontext.vala b/vala/valacodecontext.vala
index 5ee2d8246..706e0d9f8 100644
--- a/vala/valacodecontext.vala
+++ b/vala/valacodecontext.vala
@@ -632,7 +632,8 @@ public class Vala.CodeContext {
                if (target_glib == "auto") {
                        var available_glib = pkg_config_modversion ("glib-2.0");
                        if (available_glib != null && available_glib.scanf ("%d.%d", out glib_major, out 
glib_minor) >= 2) {
-                               glib_minor -= ++glib_minor % 2;
+                               glib_minor++;
+                               glib_minor -= glib_minor % 2;
                                set_target_glib_version ("%d.%d".printf (glib_major, glib_minor));
                        } else {
                                Report.warning (null, "Could not determine the version of `glib-2.0', target 
version of glib was not set");