#20710:Fixing empty string support in command recipe handler

Work Item: 20710

src/Orchard.Web/Modules/Orchard.Recipes/RecipeHandlers/CommandRecipeHandler.cs

@@ -67,8 +67,9 @@ namespace Orchard.Recipes.RecipeHandlers  {
             };
 
             foreach (var arg in args) {
-                // Switch?
-                if (arg[0] == '/') {
+                if (arg.StartsWith("/")) {
+                    //If arg is not empty and starts with '/'
+
                     int index = arg.IndexOf(':');
                     var switchName = (index < 0 ? arg.Substring(1) : arg.Substring(1, index - 1));
                     var switchValue = (index < 0 || index >= arg.Length ? string.Empty : arg.Substring(index + 1));