[moserial] Require modern Vala compiler version

[Michael J. Chudobiak <mjc src gnome org>]

commit b0b87014758483165ed2351608e460f8b0c23325
Author: Mictronics <github mictronics de>
Date:   Sat Apr 25 14:50:08 2020 +0200

    Require modern Vala compiler version

 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index c53491a..99930cb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -29,7 +29,7 @@ AC_SUBST(LDFLAGS)
 GLIB_REQUIRED=2.12.0
 GTK_REQUIRED=3.0.0
 
-AM_PROG_VALAC([0.16.0])
+AM_PROG_VALAC([0.48.5])
 
 PKG_CHECK_MODULES(MOSERIAL, glib-2.0 >= $GLIB_REQUIRED
                            gobject-2.0 >= $GLIB_REQUIRED