[gnome-usage] speedometer: drop default value of non-automatic property for newer vala

[Felipe Borges <felipeborges src gnome org>]

commit f6ae59a4d31b9a063e3eff7828bddf8dcf07e865
Author: Rasmus Thomsen <cogitri exherbo org>
Date:   Mon Sep 17 20:54:03 2018 +0200

    speedometer: drop default value of non-automatic property for newer vala

 src/speedometer.vala | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/speedometer.vala b/src/speedometer.vala
index 9d3b3f6..f307f5e 100644
--- a/src/speedometer.vala
+++ b/src/speedometer.vala
@@ -33,7 +33,7 @@ namespace Usage
 
         private Gtk.CssProvider css_provider;
 
-        private int _percentage;
+        private int _percentage = 0;
         public int percentage {
             get {
                 return _percentage;
@@ -43,7 +43,7 @@ namespace Usage
 
                 _percentage = value;
             }
-            default = 0; }
+        }
 
         construct {
             css_provider = new Gtk.CssProvider();