Fixed bad arguments to gsutil

boto is required.

BUG=261741
TBR=iannucci

Review URL: https://codereview.chromium.org/315343002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@275244 0039d316-1c4b-4281-b951-d872f2087c98

git_cache.py

@@ -252,7 +252,7 @@ class Mirror(object):
       python_fallback = True
 
     gs_folder = 'gs://%s/%s' % (self.bootstrap_bucket, self.basedir)
-    gsutil = Gsutil(self.gsutil_exe, bypass_prodaccess=True)
+    gsutil = Gsutil(self.gsutil_exe, boto_path=None, bypass_prodaccess=True)
     # Get the most recent version of the zipfile.
     _, ls_out, _ = gsutil.check_call('ls', gs_folder)
     ls_out_sorted = sorted(ls_out.splitlines())