Fix Xmlworker eating chars when parsing &

When Xmlworker encountered a '&' followed by a ' ',
it would leave the special char state without appending the ' '.

SUP-1596

Author: Samuel Huylebroeck

src/extras/itextsharp.xmlworker/iTextSharp/tool/xml/parser/state/SpecialCharState.cs

@@ -85,7 +85,7 @@ virtual public void Process(char character) {
                 this.parser.Memory().CurrentEntity().Length = 0;
              } else if (character != '#' && (character < '0' || character > '9') && (character < 'a' || character > 'z')
                     && (character < 'A' || character > 'Z') || entity.Length >= 7) {
-                 parser.Append('&').Append(entity.ToString());
+                 parser.Append('&').Append(entity.ToString()).Append(character);
                  parser.SelectState().PreviousState();
                  this.parser.Memory().CurrentEntity().Length = 0;
             } else {