[test_downloadermiddleware_httpcache] Trying hack to handle systemerror whjen importing leveldb

https://github.com/scrapy/scrapy/issues/4085

tests/test_downloadermiddleware_httpcache.py

@@ -6,6 +6,7 @@ import unittest
 import email.utils
 from contextlib import contextmanager
 import pytest
+import sys
 
 from scrapy.http import Response, HtmlResponse, Request
 from scrapy.spiders import Spider
@@ -157,7 +158,10 @@ class FilesystemStorageGzipTest(FilesystemStorageTest):
 
 class LeveldbStorageTest(DefaultStorageTest):
 
-    pytest.importorskip('leveldb')
+    try:
+        pytest.importorskip('leveldb')
+    except SystemError:
+        pass
     storage_class = 'scrapy.extensions.httpcache.LeveldbCacheStorage'