Do not write json error message to stderr

TestAssets/TestProjects/AppWithBomGlobalJson/Program.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace ConsoleApplication
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+            Console.WriteLine("Hello World!");
+        }
+    }
+}

TestAssets/TestProjects/AppWithBomGlobalJson/global.json

@@ -0,0 +1 @@
+{}

TestAssets/TestProjects/AppWithBomGlobalJson/project.json

@@ -0,0 +1,20 @@
+{
+  "version": "1.0.0-*",
+  "compilationOptions": {
+    "emitEntryPoint": true
+  },
+  "dependencies": {
+    "NETStandard.Library": "1.5.0-rc2-23930"
+  },
+  "frameworks": {
+    "netstandardapp1.5": {
+      "imports": "dnxcore50"
+    }
+  },
+  "tools": {
+    "dotnet-portable": {
+      "version": "1.0.0",
+      "target": "package"
+    }
+  }
+}