set min_timer between settlement creation

const.lua

@@ -6,6 +6,11 @@ settlements.debug = false
 -- switch for lvm
 settlements.lvm = false
 --
+-- timer between creation of two settlements
+--
+settlements.last_settlement = 0;
+settlements.min_timer = 5
+--
 --
 -- material to replace cobblestone with
 --

init.lua

@@ -1,6 +1,6 @@
---package.cpath = package.cpath .. ";/usr/share/lua/5.2/?.so"
---package.path = package.path .. ";/usr/share/zbstudio/lualibs/mobdebug/?.lua"
---require('mobdebug').start()
+package.cpath = package.cpath .. ";/usr/share/lua/5.2/?.so"
+package.path = package.path .. ";/usr/share/zbstudio/lualibs/mobdebug/?.lua"
+require('mobdebug').start()
 
 settlements = {}
 settlements.modpath = minetest.get_modpath("settlements");
@@ -59,6 +59,13 @@ minetest.register_on_generated(function(minp, maxp)
     -- randomly try to build settlements
     -- 
     if math.random(1,10)<6 then 
+      --
+      -- time between cration of two settlements
+      --
+      if os.difftime(os.time(), settlements.last_settlement) < settlements.min_timer 
+      then
+        return
+      end
       --
       -- don't build settlement underground
       --
@@ -112,6 +119,10 @@ minetest.register_on_generated(function(minp, maxp)
             return
           end
           --
+          -- set timestamp of actual settlement
+          --
+          settlements.last_settlement = os.time()
+          --
           -- evaluate settlement_info and prepair terrain
           --
           if settlements.lvm == true