配置增加默认值

source/DeviceLibrary/acSingleStore/AC_SA_BoxBean.cs

@@ -115,6 +115,11 @@ namespace OnlineStore.DeviceLibrary
             try
             {
                 string vfile = Application.StartupPath + ConfigAppSettings.GetValue(Setting_Init.VisionConfigFile);
+
+                if (String.IsNullOrEmpty(vfile))
+                {
+                    vfile = @"\Camera.json";
+                }
                 if (!String.IsNullOrEmpty(vfile))
                 {
                     vision = new Asa.Camera.VisionLib(vfile, "RollingLogFileAppender");