fix nursery BC

fixes #1062 (closed)

In theory all childs chould have .amp, seems like that isn't true.

src/pregmod/widgets/pregmodWidgets.tw

@@ -552,6 +552,15 @@
 	<<run delete $args[0].amp>>
 	<<run delete $args[0].missingLegs>>
 	<<run delete $args[0].missingArms>>
+<<elseif ndef $args[0].arm>>
+	<<set $args[0].arm = {
+		left: new App.Entity.LimbState(),
+		right: new App.Entity.LimbState()
+	}>>
+	<<set $args[0].leg = {
+		left: new App.Entity.LimbState(),
+		right: new App.Entity.LimbState()
+	}>>
 <</if>>
 
 <<if hasAnyProstheticLimbs($args[0])>>