Fixed bug in bim.select_assigned_product

It was trying to call method `Drawingcls.get_active_object()` that didn't exist

src/blenderbim/blenderbim/bim/module/drawing/operator.py

@@ -1704,4 +1704,4 @@ class SelectAssignedProduct(bpy.types.Operator, Operator):
     bl_options = {"REGISTER", "UNDO"}
 
     def _execute(self, context):
-        core.select_assigned_product(tool.Drawing)
+        core.select_assigned_product(tool.Drawing, context)

src/blenderbim/blenderbim/core/drawing.py

@@ -380,8 +380,8 @@ def sync_references(ifc, collector, drawing_tool, drawing=None):
             drawing_tool.sync_object_representation(reference_obj)
 
 
-def select_assigned_product(drawing):
+def select_assigned_product(drawing, context):
-    drawing.select_assigned_product()
+    drawing.select_assigned_product(context)
 
 
 def activate_drawing_view(ifc, drawing_tool, drawing):

src/blenderbim/blenderbim/tool/drawing.py

@@ -1367,8 +1367,8 @@ class Drawing(blenderbim.core.tool.Drawing):
         return reference.ReferencedDocument
 
     @classmethod
-    def select_assigned_product(cls):
+    def select_assigned_product(cls, context):
-        obj = cls.get_active_object()
+        obj = context.active_object
         element = tool.Ifc.get_entity(obj)
         product = cls.get_assigned_product(element)
         if product: