[gnome-chess] Constructors of abstract classes should not be public

[Rico Tzschichholz <ricotz src gnome org>]

commit c5053a2b04d73e96feda19df194d9ab0f1a37351
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Mar 18 10:09:28 2019 +0100

    Constructors of abstract classes should not be public

 src/chess-engine.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/chess-engine.vala b/src/chess-engine.vala
index fbf630c..6b69895 100644
--- a/src/chess-engine.vala
+++ b/src/chess-engine.vala
@@ -51,7 +51,7 @@ public abstract class ChessEngine : Object
         }
     }
 
-    public ChessEngine (string binary, string[] args, uint delay_seconds)
+    protected ChessEngine (string binary, string[] args, uint delay_seconds)
     {
         this.binary = binary;
         this.args = args;