Description: Don't expect to find a thumbnail that has been removed

(for copyright reasons)

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Bug-Debian: https://bugs.debian.org/1053672
Forwarded: no

--- a/openpyxl/reader/tests/test_excel.py
+++ b/openpyxl/reader/tests/test_excel.py
@@ -181,7 +181,6 @@ class TestExcelReader:
             'xl/theme/theme1.xml',
             'xl/styles.xml',
             'xl/worksheets/sheet1.xml',
-            'docProps/thumbnail.jpeg',
             'docProps/core.xml',
             'docProps/app.xml'
         ]