ninjalog_uploader_wrapper.py: handle broken config file

This is to make the script work even when config file is broken.

Change-Id: I6c2a090b01026b5747137bcc9fdec0bd5c03f75e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3607373
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Fumitoshi Ukai <ukai@google.com>
Commit-Queue: Fumitoshi Ukai <ukai@google.com>

ninjalog_uploader_wrapper.py

@@ -23,7 +23,16 @@ VERSION = 3
 def LoadConfig():
   if os.path.isfile(CONFIG):
     with open(CONFIG, 'r') as f:
-      config = json.load(f)
+      try:
+        config = json.load(f)
+      except Exception:
+        # Set default value when failed to load config.
+        config = {
+            'is-googler': ninjalog_uploader.IsGoogler(),
+            'countdown': 10,
+            'version': VERSION,
+        }
+
       if config['version'] == VERSION:
         config['countdown'] = max(0, config['countdown'] - 1)
         return config