Fix #1288 - error when importing consecutive files.

src/ifcblenderexport/blenderbim/bim/module/owner/data.py

@@ -8,6 +8,14 @@ class Data:
     addresses = {}
     roles = {}
 
+    @classmethod
+    def purge(cls):
+        cls.is_loaded = False
+        cls.people = {}
+        cls.organisations = {}
+        cls.addresses = {}
+        cls.roles = {}
+
     @classmethod
     def load(cls):
         file = IfcStore.get_file()