Fix line endings in JsonStructuredOutput to repair repo sync tool

Summary: In spite of the `.editorconfig`, we ended up with mixed line endings in a new source file again, breaking the sync tool that pushes changes to github.

Differential Revision: D54423708

fbshipit-source-id: 3ffa3a361609941d05cdfed3e52a9dbaa8d70e09

CommandInfrastructure/JsonStructuredOutput.cs

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.IO;
 using System.Text;
 using System.Text.Json;