[gnome-mines] Removed unused public setter

[Robert Roth <robertroth src gnome org>]

commit 49e13cc16b49eaa0f2f85263a0808c19ef36f740
Author: Robert Roth <robert roth off gmail com>
Date:   Sun Oct 14 01:06:00 2018 +0300

    Removed unused public setter

 src/minefield.vala | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
---
diff --git a/src/minefield.vala b/src/minefield.vala
index 2dfaaea..ab10015 100644
--- a/src/minefield.vala
+++ b/src/minefield.vala
@@ -85,7 +85,6 @@ public class Minefield : Object
     public uint n_flags
     {
         get { return _n_flags; }
-        set { _n_flags = value; }
     }
 
     public bool use_autoflag
@@ -265,7 +264,7 @@ public class Minefield : Object
         locations[x, y].cleared = true;
         _n_cleared++;
         if (locations[x, y].flag == FlagType.FLAG)
-            n_flags--;
+            _n_flags--;
         locations[x, y].flag = FlagType.NONE;
         redraw_sector (x, y);
         marks_changed ();
@@ -289,9 +288,9 @@ public class Minefield : Object
             return;
 
         if (flag == FlagType.FLAG)
-            n_flags++;
+            _n_flags++;
         else if (locations[x, y].flag == FlagType.FLAG)
-            n_flags--;
+            _n_flags--;
 
         locations[x, y].flag = flag;
         redraw_sector (x, y);