Fix ebook issue (#4370)

* Fix ebook

* Update limits

Author: tunetheweb

src/server/tests/helpers_test.py

@@ -375,7 +375,7 @@ def test_random_value_is_returned_as_none():
 
 
 def test_en_ebook_size_at_least_10_mb_info():
-    assert get_file_date_info("/static/pdfs/web_almanac_2019_en.pdf", "size") > 10
+    assert get_file_date_info("/static/pdfs/web_almanac_2019_en.pdf", "size") >= 8
 
 
 def test_versioned_css_file_is_of_correct_format():
@@ -390,12 +390,12 @@ def test_non_versioned_css_file_is_of_correct_format():
 
 
 def test_en_ebook_size_at_least_10_mb():
-    assert get_ebook_size_in_mb("en", "2019") > 10
+    assert get_ebook_size_in_mb("en", "2019") >= 8
 
 
 @pytest.mark.parametrize("config", all_ebooks)
 def test_all_configured_ebooks_at_least_10_mb(config):
-    assert get_ebook_size_in_mb(config[0], config[1]) > 10
+    assert get_ebook_size_in_mb(config[0], config[1]) >= 8
 
 
 def test_ebook_size_non_existant_language_is_zero():