ninjalog_uploader_wrapper: do not use binary read/write for json

This is for python3 compatibility.

Bug: b/177465438
Change-Id: I4770136ea702bcaf7a8b644ef842db2f1a7d1200
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2717272Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Chris Hall <chrishall@chromium.org>
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>

ninjalog_uploader_wrapper.py

@@ -22,7 +22,7 @@ VERSION = 2
 
 def LoadConfig():
   if os.path.isfile(CONFIG):
-    with open(CONFIG, 'rb') as f:
+    with open(CONFIG, 'r') as f:
       config = json.load(f)
       if config['version'] == VERSION:
         config['countdown'] = max(0, config['countdown'] - 1)
@@ -37,7 +37,7 @@ def LoadConfig():
 
 
 def SaveConfig(config):
-  with open(CONFIG, 'wb') as f:
+  with open(CONFIG, 'w') as f:
     json.dump(config, f)