Do not crash for non URL (i.e. SSH) remotes.

Without this change, having an SSH remote configured makes `git cl
archive` crash:

Traceback (most recent call last):
  File "/usr/local/google/home/fmayer/depot_tools/metrics.py", line 267, in print_notice_and_exit
    yield
  File "/usr/local/google/home/fmayer/depot_tools/git_cl.py", line 5553, in <module>
    sys.exit(main(sys.argv[1:]))
  File "/usr/local/google/home/fmayer/depot_tools/git_cl.py", line 5535, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/usr/local/google/home/fmayer/depot_tools/subcommand.py", line 252, in execute
    return command(parser, args[1:])
  File "/usr/local/google/home/fmayer/depot_tools/metrics.py", line 252, in _inner
    return self._collect_metrics(func, command_name, *args, **kwargs)
  File "/usr/local/google/home/fmayer/depot_tools/metrics.py", line 232, in _collect_metrics
    gclient_utils.reraise(exception[0], exception[1], exception[2])
  File "/usr/local/google/home/fmayer/depot_tools/metrics.py", line 205, in _collect_metrics
    result = func(*args, **kwargs)
  File "/usr/local/google/home/fmayer/depot_tools/git_cl.py", line 3786, in CMDarchive
    for cl, status in statuses
  File "/usr/local/google/home/fmayer/depot_tools/git_cl.py", line 3599, in get_cl_statuses
    cl.EnsureAuthenticated(force=False, refresh=True)
  File "/usr/local/google/home/fmayer/depot_tools/git_cl.py", line 1757, in EnsureAuthenticated
    if urllib.parse.urlparse(self.GetRemoteUrl()).scheme != 'https':
  File "/usr/lib/python2.7/urlparse.py", line 143, in urlparse
    tuple = urlsplit(url, scheme, allow_fragments)
  File "/usr/lib/python2.7/urlparse.py", line 201, in urlsplit
    i = url.find(':')
AttributeError: 'NoneType' object has no attribute 'find'

Change-Id: I6f794f11d3ed5e3dbedfe278ded660fca32abda6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2030505
Commit-Queue: Florian Mayer <fmayer@google.com>
Reviewed-by: Anthony Polito <apolito@google.com>
diff --git a/git_cl.py b/git_cl.py
index 530fd79..543b915 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -1754,7 +1754,11 @@
     if not isinstance(cookie_auth, gerrit_util.CookiesAuthenticator):
       return
 
-    if urllib.parse.urlparse(self.GetRemoteUrl()).scheme != 'https':
+    remote_url = self.GetRemoteUrl()
+    if remote_url is None:
+      print('WARNING: invalid remote')
+      return
+    if urllib.parse.urlparse(remote_url).scheme != 'https':
       print('WARNING: Ignoring branch %s with non-https remote %s' %
             (self.branch, self.GetRemoteUrl()))
       return