Fix a handful of little bugs

Refactor of manual scrobbling missed an import
KoReader book removed in sqlite fails import
Looking up album by name and artists screws up on MBid unique

vrobbler/apps/books/koreader.py

@@ -129,6 +129,8 @@ def build_scrobbles_from_pages(
     book_read_time_map = {}
     for page_row in rows:
         koreader_id = page_row[KoReaderPageStatColumn.ID_BOOK.value]
+        if koreader_id not in book_id_map.keys():
+            continue
         page_number = page_row[KoReaderPageStatColumn.PAGE.value]
         ts = page_row[KoReaderPageStatColumn.START_TIME.value]
         book_id = book_id_map[koreader_id][0]