Closes netork#117.
A Yealink is a desk phone. It inherited AccessPointDriver because nothing better
existed, and netOrk reads that role to populate its wireless page, its AP
profile pickers and its SSID drift view — so a phone appeared in all three.
napalm-device-types now has PhoneDriver. TYPE_LABEL comes from it, so the local
override is gone.
The two failing fingerprint tests were asserting the opposite of a deliberate
decision. HTTP_FINGERPRINT carries "yealink" as a heavy but *not* mandatory
rule, with the reason written next to it: some models answer / with a redirect
to their API page, whose body says "yealink" nowhere, and a mandatory rule
disqualifies the driver whenever its pattern is absent. Making it mandatory
would rule out a real phone.
The tests demanded it be mandatory, and the Cisco test then asserted `not
all(...)` over an empty list, which is False. Both now check the property that
actually protects against a false match: none of this driver's patterns appear
on a Cisco page, so it contributes no score and never wins.