HTTP: stop checking Expires header

This header is dropped by some CDN when getting a cache hit

src/surykatka/http.py

@@ -252,13 +252,14 @@ def checkHttpStatus(
             header_dict[header_key] = header_value
 
     # Store key only, because of non stability
-    # 'Etag', 'Last-Modified', 'Set-Cookie', 'Date', 'Age', 'Expires'
+    # 'Etag', 'Last-Modified', 'Set-Cookie', 'Date', 'Age'
     key_only_header_list = [
         "Etag",
         "Last-Modified",
         "Set-Cookie",
         "Age",
-        "Expires",
+        # Expires is dropped by some CDN when getting a cache hit
+        # "Expires",
     ]
     for header_key in key_only_header_list:
         header_value = response.headers.get(header_key, None)

tests/test_http.py

@@ -1029,7 +1029,6 @@ class SurykatkaHttpTestCase(unittest.TestCase):
             "Last-Modified",
             "Set-Cookie",
             "Age",
-            "Expires",
         ]
         blacklist_header_list = [
             "Foo",