In the server.properties file there is an option

spawn-npcs=true

Intended behaviour
When setting this to false, villagers should not generate in new villages.

What is actually happening
When testing on a vanilla server, it works as intended, villagers do not spawn in newly generated villages.

When testing this on both Craftbukkit and Spigot servers the villagers spawn in newly generated villages. The command `/summon villagers` does not work (as intended)

 
Steps to reproduce:

1. Create a fresh new world
2. Join the world, and locate a village (use command '/locate Village' and click the coords to teleport to said village)
3. Observe that there are in fact villagers there, when there should not be.

Testing environment
I have tested this on fresh builds of Craftbukkit and Spigot

Craftbukkit:
CraftBukkit version git-Bukkit-56118c6

Spigot:
CraftBukkit version git-Spigot-56f8471-56118c6