gsm: couldn't get secrets

["Vitja Makarov" <vitja makarov gmail com>]

Hi!

I was trying to get nm working with my phone/operator. I've edited my
GSM connection with connection-editor.
And here we are.

First of all I found that pppd doesn't work if setpgid(2) were called for it.
Then I commented it out, and pppd worked for me.

In connection-editor i've filled username/password fields.
But when pppd plugin calls NeedSecrets it throws exception "Cleared
secrets, but setting didn't need any secrets."
NMSettingGSM doesn't provide need_secrets call, I looked at pppoe case
and implemented that, but it
simply asks me for a pin, but i don't know what it is.

I think it's simple to solve this. We need to move all ppp-related password
to ppp-setting, and provide handlers common for cdma/gsm/pppoe/...

and let gsm setting ask for a pin/puk

vitja.