Code review changes

src/Microsoft.AspNet.Configuration.Json/JsonConfigurationSource.cs

@@ -11,7 +11,7 @@ namespace Microsoft.AspNet.Configuration.Json
     {
         public JsonConfigurationSource(string path)
         {
-            if (string.IsNullOrEmpty(path) || string.IsNullOrWhiteSpace(path))
+            if (string.IsNullOrEmpty(path))
             {
                 // TODO: exception message localization
                 throw new ArgumentException("File path must be a non-empty string", "path");

src/Microsoft.AspNet.ConfigurationModel/Sources/IniFileConfigurationSource.cs

@@ -19,7 +19,7 @@ namespace Microsoft.AspNet.ConfigurationModel.Sources
         /// <param name="path">The path and file name to load.</param>
         public IniFileConfigurationSource(string path)
         {
-            if (string.IsNullOrEmpty(path) || string.IsNullOrWhiteSpace(path))
+            if (string.IsNullOrEmpty(path))
             {
                 // TODO: exception message localization
                 throw new ArgumentException("File path must be a non-empty string", "path");