crowdin: Add missing import

* Forgot "re", will result in an error when trying to download from crowdin

Change-Id: I8c04f002560d0da38260608f85d574be05046741
diff --git a/crowdin_sync.py b/crowdin_sync.py
index 34c83e0..d191af1 100755
--- a/crowdin_sync.py
+++ b/crowdin_sync.py
@@ -28,6 +28,7 @@
 import json
 import git
 import os
+import re
 import subprocess
 import sys
 import yaml