Empty lists can not be uploaded

Author: mbasil09

intermine/lists/listmanager.py

@@ -265,6 +265,11 @@ def create_list(
 
         if name is None:
             name = self.get_unused_list_name()
+        if len(content) <= 0:
+            print("Lists must have one or more elements - the current list has 0")
+            print(
+                "Please create a valid list with at least one element and create the list again")
+            return
 
         item_content = content