[test_download] Remove references to "file" in test definitions

test/test_download.py

@@ -89,7 +89,7 @@ def generator(test_case):
 
         for tc in test_cases:
             info_dict = tc.get('info_dict', {})
-            if not tc.get('file') and not (info_dict.get('id') and info_dict.get('ext')):
+            if not (info_dict.get('id') and info_dict.get('ext')):
                 raise Exception('Test definition incorrect. The output file cannot be known. Are both \'id\' and \'ext\' keys present?')
 
         if 'skip' in test_case:
@@ -116,7 +116,7 @@ def generator(test_case):
         expect_warnings(ydl, test_case.get('expected_warnings', []))
 
         def get_tc_filename(tc):
-            return tc.get('file') or ydl.prepare_filename(tc.get('info_dict', {}))
+            return ydl.prepare_filename(tc.get('info_dict', {}))
 
         res_dict = None