Remove two lines not covered.

Author: ninedan

StyleCop.Analyzers/StyleCop.Analyzers/Helpers/XmlCommentHelper.cs

@@ -7,7 +7,6 @@ namespace StyleCop.Analyzers.Helpers
 {
     using System.Linq;
     using System.Text;
-    using System.Text.RegularExpressions;
     using System.Xml.Linq;
     using Microsoft.CodeAnalysis;
     using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -312,11 +311,6 @@ internal static string NormalizeWhiteSpace(this string text)
 
             int length = text.Length;
 
-            if (length == 0)
-            {
-                return string.Empty;
-            }
-
             bool lastSpace = false;
 
             bool diff = false;