only change mac proxy under current mac location

[laye0619]

System and Shadowsocksx-NG version:

• macOS 10.12.4
• Shadowsocksx-NG 1.5

Expected behavior:
when turning on auto mode, just change mac proxy in current macos location instead of all of location profiles.

Actual behavior:

(N/A for feature requests)

Steps to reproduce:

(N/A for feature requests)

How often does this happen?

(N/A for feature requests)

ss-local.log

Please upload the ss-local.log file here the file is in ~/Library/Logs

1. Open 'Advanced Settings -> enable Verbose Mode'
2. Continue run Shadowsocksx-NG for 5 minutes
3. Upload the ~/Library/Logs/ss-local.log here (with or without compress)

Application log

Open the Console.app and search Shadowsocksx-NG
Copy paste the log here

Crash Log

If the app crashes and pop up a crash log, please copy and paste here