Fix an error in previous Conditional section patch

an off by one mistake in the change, led to error on correct
document where the end of the included entity was exactly
the end of the conditional section, leading to regtest failure

parser.c

@@ -6916,7 +6916,7 @@ xmlParseConditionalSections(xmlParserCtxtPtr ctxt) {
 				 NULL, NULL);
 	}
 	if ((ctxt-> instate != XML_PARSER_EOF) &&
-	    ((ctxt->input->cur + 3) < ctxt->input->end))
+	    ((ctxt->input->cur + 3) <= ctxt->input->end))
 	    SKIP(3);
     }
 }