[FS#1451] Access points should not run a DHCP server after installation

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - whitequark (whitequark) 

Attached to Project - OpenWrt/LEDE Project
Summary - Access points should not run a DHCP server after installation
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Medium
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - Take an [UniFi AP](https://openwrt.org/toh/ubiquiti/unifi) or [UniFi AC AP](https://openwrt.org/toh/ubiquiti/unifiac) and deploy OpenWRT to it. It'll come up as an authoritative DHCP server, which is (a) completely unexpected, as no reasonable network will have authoritative DHCP servers running on access points, and (b) disruptive.

I think that default configuration for access points should be any of, in the order decreasing preference:
  * DHCP client with fallback to static configuration
  * Just DHCP client
  * Static configuration

More information can be found at the following URL:
https://bugs.openwrt.org/index.php?do=details&task_id=1451