Support PyPDF2 version 3.0.0

PdfFileReader and PdfFileWriter raise a deprecation exception at run time but
the new names have been introduced only in version 2.0.0, 6 months ago.

Closes #11961
(grafted from 03e7faead7e135035cdcdf7047eb16b37ed956e0)

--HG--
branch : 6.0

modules/stock_package_shipping_dpd/stock.py

@@ -7,7 +7,11 @@ from itertools import zip_longest
 
 from lxml import etree
 from zeep.exceptions import Fault
-from PyPDF2 import PdfFileReader, PdfFileWriter
+
+try:
+    from PyPDF2 import PdfReader, PdfWriter
+except ImportError:
+    from PyPDF2 import PdfFileReader as PdfReader, PdfFileWriter as PdfWriter
 
 from trytond.i18n import gettext
 from trytond.pool import Pool, PoolMeta
@@ -166,9 +170,9 @@ class CreateDPDShipping(Wizard):
 
         labels = []
         labels_pdf = BytesIO(shipment_response.parcellabelsPDF)
-        reader = PdfFileReader(labels_pdf)
+        reader = PdfReader(labels_pdf)
         for page_num in range(reader.getNumPages()):
-            new_pdf = PdfFileWriter()
+            new_pdf = PdfWriter()
             new_label = BytesIO()
             new_pdf.addPage(reader.getPage(page_num))
             new_pdf.write(new_label)