fix typo with new python

coldcall.py

@@ -36,7 +36,7 @@ class ColdCall():
         previous_questions = defaultdict(int)
 
         for fn in listdir("./data/"):
-            if re.match("call_list-\d{4}-\d{2}-\d{2}.tsv", fn):
+            if re.match(r"call_list-\d{4}-\d{2}-\d{2}.tsv", fn):
                 with open(f"./data/{fn}", 'r') as f:
                     for row in DictReader(f, delimiter="\t"):
                         if not row["answered"] == "FALSE":