FIX: resolve deprecation for collections module

See https://docs.python.org/3/library/collections.abc.html for details.

src/caosdb/apiutils.py

@@ -30,7 +30,7 @@ import os
 import random
 import sys
 import tempfile
-from collections import Iterable
+from collections.abc import Iterable
 from subprocess import call
 
 from . import (BOOLEAN, DATETIME, DOUBLE, FILE, INTEGER, REFERENCE, TEXT,