fix(): fix APP_SUMMARY not being translated

Author: SkyzohKey

src/Ricin.vala

@@ -1,7 +1,7 @@
 public class Ricin.Ricin : Gtk.Application {
   const string GETTEXT_PACKAGE = "ricin";
   public static const string APP_NAME = "Ricin";
-  public static const string APP_SUMMARY = "<b>Ricin</b> aims to be a <i>secure, lightweight, hackable and fully-customizable</i> chat client using the awesome and open-source <b>ToxCore</b> library.";
+  public static const string APP_SUMMARY = _("<b>Ricin</b> aims to be a <i>secure, lightweight, hackable and fully-customizable</i> chat client using the awesome and open-source <b>ToxCore</b> library.");
   public static const string APP_VERSION = "0.0.6";
   public static const string RES_BASE_PATH = "/chat/tox/ricin/";