Use platform.machine() instead of os.uname().machine (UNIX favors)

Describe the bug

Cannot start hummingbot because os.uname().machine does not work on windows in D:\Crypto\hummingbot\hummingbot\core\gateway\__init__.py.

Steps To Reproduce

• Follow steps to build hummingbot from source on windows here
• Checkout development branch
• Start hummingbot

Release version

v1.3.0

Error message

$ winpty python bin/hummingbot.py
Traceback (most recent call last):
  File "bin/hummingbot.py", line 15, in <module>
    from hummingbot.client.config.config_helpers import (
  File "D:\Crypto\hummingbot\hummingbot\client\config\config_helpers.py", line 24, in <module>
    from hummingbot.client.config.global_config_map import global_config_map
  File "D:\Crypto\hummingbot\hummingbot\client\config\global_config_map.py", line 13, in <module>
    from hummingbot.core.rate_oracle.rate_oracle import RateOracle, RateOracleSource
  File "D:\Crypto\hummingbot\hummingbot\core\rate_oracle\rate_oracle.py", line 15, in <module>
    from hummingbot.core.rate_oracle.utils import find_rate
  File "D:\Crypto\hummingbot\hummingbot\core\rate_oracle\utils.py", line 4, in <module>
    from hummingbot.core.gateway.utils import unwrap_token_symbol
  File "D:\Crypto\hummingbot\hummingbot\core\gateway\__init__.py", line 16, in <module>
    GATEWAY_DOCKER_TAG: str = "20220401-arm" if os.uname().machine in {"arm64", "aarch64"} else "20220329"
AttributeError: module 'os' has no attribute 'uname'