Fixed grammar in sqlite's DatabaseOperations.bulk_batch_size()'s docstring.

django/db/backends/sqlite3/operations.py

@@ -20,8 +20,8 @@ class DatabaseOperations(BaseDatabaseOperations):
         SQLite has a compile-time default (SQLITE_LIMIT_VARIABLE_NUMBER) of
         999 variables per query.
 
-        If there is just single field to insert, then we can hit another
-        limit, SQLITE_MAX_COMPOUND_SELECT which defaults to 500.
+        If there's only a single field to insert, the limit is 500
+        (SQLITE_MAX_COMPOUND_SELECT).
         """
         limit = 999 if len(fields) > 1 else 500
         return (limit // len(fields)) if len(fields) > 0 else len(objs)