fixed #123263, the encoding is mandatory in a textdecl. Daniel

* parser.c: fixed #123263, the encoding is mandatory in a textdecl.
Daniel
diff --git a/include/libxml/xmlerror.h b/include/libxml/xmlerror.h
index 2def816..1fcdf96 100644
--- a/include/libxml/xmlerror.h
+++ b/include/libxml/xmlerror.h
@@ -181,6 +181,7 @@
     XML_WAR_LANG_VALUE, /* 98 */
     XML_WAR_NS_URI, /* 99 */
     XML_WAR_NS_URI_RELATIVE, /* 100 */
+    XML_ERR_MISSING_ENCODING, /* 101 */
     XML_NS_ERR_XML_NAMESPACE = 200,
     XML_NS_ERR_UNDEFINED_NAMESPACE, /* 201 */
     XML_NS_ERR_QNAME, /* 202 */