Strip off footer navigation links for Ward

Since the text is now "Previous Chapter" instead of "Last Chapter" they weren't getting removed.

lib/convert.js

@@ -378,7 +378,10 @@ function getBodyXML(chapter, contentEl) {
 
 function isEmptyOrGarbage(el) {
   const text = el.textContent.trim();
-  return text === "" || text.startsWith("Last Chapter") || text.startsWith("Next Chapter");
+  return text === "" ||
+         text.startsWith("Last Chapter") ||
+         text.startsWith("Previous Chapter") ||
+         text.startsWith("Next Chapter");
 }
 
 function escapeRegExp(str) {