Fix issue when creating an activity from a prospect

bizdev/admin.py

@@ -400,7 +400,7 @@ class ActivityAdmin(SyncedObjectAdmin):
             try:
                 prospect_id = request.GET['prospect']
                 prospect = Prospect.objects.get(id=prospect_id)
-                form.base_fields['prospects'].initial = prospect
+                form.base_fields['prospects'].initial = [prospect]
                 form.base_fields['related_user'].initial = request.user
 
                 # You can set other fields based on the prospect