fix: Test-Slave Incubators save/loading (#712)

Author: VanWeapon

objects/obj_ini/Create_0.gml

@@ -152,7 +152,8 @@ serialize = function(){
         artifact_struct: artifact_struct_trimmed,
         marine_structs: marines,
         squad_structs: squads,
-        equipment: equipment
+        equipment: equipment,
+        gene_slaves: gene_slaves
         // marines,
         // squads
     }
@@ -250,6 +251,10 @@ deserialize = function(save_data){
             }
         }
     }
+
+    if(struct_exists(save_data, "gene_slaves")){
+        variable_struct_set(obj_ini, "gene_slaves", save_data.gene_slaves);
+    }
 }