[emigration] remove emigrating units from burrows

changelog.txt

@@ -40,6 +40,7 @@ Template for new versions:
 - `fix/loyaltycascade`: fix lookup of associated unit metadata when the metadata list is sparse (that is, the script was sometimes failing to fix the loyalties of renegade units because it was failing to find those units' metadata)
 - `quickfort`: reject tiles for building that contain magma or deep water
 - `armoks-blessing`: fix error when making class "Normal" attributes legendary
+- `emigration`: remove units from burrows when they emigrate
 
 ## Misc Improvements
 - `gui/reveal`: show aquifers even when not in mining mode

emigration.lua

@@ -1,6 +1,3 @@
---Allow stressed dwarves to emigrate from the fortress
--- For 34.11 by IndigoFenix; update and cleanup by PeridexisErrant
--- old version:  http://dffd.bay12games.com/file.php?id=8404
 --@module = true
 --@enable = true
 
@@ -81,6 +78,11 @@ function desert(u,method,civ)
         end
     end
 
+    -- unburrow
+    for _, burrow in ipairs(df.global.plotinfo.burrows.list) do
+        dfhack.burrows.setAssignedUnit(burrow, u, false)
+    end
+
     -- erase the unit from the fortress entity
     for k,v in ipairs(fort_ent.histfig_ids) do
         if v == hf_id then