Fix space issue in AntStructure.DTDPrinter

Task AntStructure renders a project DTD. In AntStructure class DTDPrinter, line 327, a single statement is used to concatenate a list of enumerated values which are valid for an attribute. The list is enclosed in parentheses. At line 348 the string "#IMPLIED" is appended to all attribute definitions regardless of type. For other types like Boolean and CDATA, a space is appended. Not for these enumerations. This results in a DTD validation error. Ref [XERCES definition](https://xerces.apache.org/xerces-j/apiDocs/org/apache/xerces/utils/XMLMessages.html#MSG_SPACE_REQUIRED_BEFORE_DEFAULTDECL_IN_ATTDEF)

The full message displayed in VSCode may be different from elsewhere:

    White space is required before the attribute default in the declaration
    of attribute "x" for element "y".
    xml(MSG_SPACE_REQUIRED_BEFORE_DEFAULTDECL_IN_ATTDEF)

This simple one-line change appends the space character required to avoid that error.

**Note:** This should not be modified into a change on the `joinAlts` Collector which surrounds values in parentheses. That Collector is used elsewhere where regex syntax is applied immediately after. See line 298. That asterisk cannot be separated from the values with a space. The space must only be applied to line 327.

1 files changed, 4 insertions, 0 deletions

diff --git a/contributors.xml b/contributors.xml
index 4e88f276c..8de1b86d1 100644
--- a/contributors.xml
+++ b/contributors.xml
@@ -1784,6 +1784,10 @@
     <last>Zezula</last>
   </name>
   <name>
+    <first>Tony</first>
+    <last>Gravagno</last>
+  </name>
+  <name>
     <first>Trejkaz</first>
     <last>Xaoza</last>
   </name>