[gnome-chess] Don't kill a broken chess-engine twice

[Sahil Sareen <ssareen src gnome org>]

commit 97263dd6ccfc389273495742d6672bfad0ac217b
Author: Sahil Sareen <sahil sareen hotmail com>
Date:   Sun Jul 19 22:04:38 2015 +0530

    Don't kill a broken chess-engine twice
    
    https://bugzilla.gnome.org/show_bug.cgi?id=724504

 src/chess-engine.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/chess-engine.vala b/src/chess-engine.vala
index ad6b339..ca6b83d 100644
--- a/src/chess-engine.vala
+++ b/src/chess-engine.vala
@@ -101,7 +101,7 @@ public abstract class ChessEngine : Object
     private void engine_stopped_cb (Pid pid, int status)
     {
         Process.close_pid (pid);
-        pid = 0;
+        this.pid = 0;
         stopped ();
     }