fix comparison of configs in Save As test

newer config structures will convert old configs to the new fields'
defaults, meaning the after won't be the same as the before once there's
a proto change not present in the original file (such as with this proto
bump for 0.7.9), so just do a more rudimentary compare

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

tests/test_gui.py

@@ -275,4 +275,4 @@ async def test_save_as(config_binary, tmp_path):
     with open('/tmp/gptest', 'rb') as new_file:
         test_config_binary = new_file.read()
     test_config = get_config(test_config_binary)
-    assert original_config == test_config
+    assert original_config.boardVersion == test_config.boardVersion