fix log not scrolled to bottom when first shown

shadowsocks-csharp/View/LogForm.Designer.cs

@@ -95,6 +95,7 @@
             this.Text = "Log Viewer";
             this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.LogForm_FormClosing);
             this.Load += new System.EventHandler(this.LogForm_Load);
+            this.Shown += new System.EventHandler(this.LogForm_Shown);
             this.ResumeLayout(false);
             this.PerformLayout();
 

shadowsocks-csharp/View/LogForm.cs

@@ -105,5 +105,10 @@ namespace Shadowsocks.View
         {
             this.Close();
         }
+
+        private void LogForm_Shown(object sender, EventArgs e)
+        {
+            textBox1.ScrollToCaret();
+        }
     }
 }