AG connecting to a proxy which is not added yet

[zzebrum]

Steps to reproduce

1. Settings - Network - Proxy settings
2. enable proxy

Expected behavior

since there is no proxy added, AG should not restart the protection and connect to the nonexistent proxy.

Actual behavior

notification about AG connected to a proxy, protection restarts.

[Revertron]

Done.

[zzebrum]

1. Add proxy server
2. Connect to it
3. Delete the server from the list

Actual behavior: AG connected to the proxy

Expected behavior: We should handle the situation

[sfionov]

Also there is an UI problem:
Size of proxy adding dialog is halved if I switch between apps while filling that dialog.

[aspasskaya]

1. Add proxy server
2. Connect to it
3. Delete the server from the list

Expected behavior: Proxy disabled.
Actual behavior:

[admitrevskiy]

Done.

Testing instructions for QA:
-Reinstall AG
-Try to reproduce the following issues:

• AG connecting to a proxy which is not added yet #2543 (comment)
• AG connecting to a proxy which is not added yet #2543 (comment)

[TheHasagi]

Fixes should be available with the nearest updates.