test: detect OS consistently using platform.system()

test/functional/feature_config_args.py

@@ -6,8 +6,8 @@
 
 import os
 from pathlib import Path
+import platform
 import re
-import sys
 import tempfile
 import time
 
@@ -116,7 +116,7 @@ class ConfArgsTest(BitcoinTestFramework):
     def test_config_file_log(self):
         # Disable this test for windows currently because trying to override
         # the default datadir through the environment does not seem to work.
-        if sys.platform == "win32":
+        if platform.system() == "Windows":
             return
 
         self.log.info('Test that correct configuration path is changed when configuration file changes the datadir')
@@ -339,7 +339,7 @@ class ConfArgsTest(BitcoinTestFramework):
     def test_ignored_default_conf(self):
         # Disable this test for windows currently because trying to override
         # the default datadir through the environment does not seem to work.
-        if sys.platform == "win32":
+        if platform.system() == "Windows":
             return
 
         self.log.info('Test error is triggered when bitcoin.conf in the default data directory sets another datadir '