I found no tools to do that for me, so I made this. Not a masterpiece, but it WORKS.

put the .conf file in ~/.config/toggleproxy.conf and modify it as your need, for example, to create a new profile, see this example If you only want to use socks proxy settings, you can delete the http, https, ftp lines in the config. after configuration, to switch your profile, enter:

$ toggleproxy [your-profile-in-here]

or to turn off the proxies:

$ toggleproxy none

and your Gnome proxy settings will be unset.