Run presubmit checks without GerritAccessor if GERRIT_HOST is not set.

When a repository doesn't work with Gerrit, it doesn't make sense to
create GerritAccessor and pass it to presubmit checks.
gerrit.host is stored into git config when codereview.settings file contains GERRIT_HOST item.

Change-Id: I9740950caf85a1da9a6e4ae12e3612625cf0cec5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3687235
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Auto-Submit: Aleksey Khoroshilov <akhoroshilov@brave.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
diff --git a/git_cl.py b/git_cl.py
index c22c682..35767c1 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -805,6 +805,12 @@
       return False
     return None
 
+  def GetIsGerrit(self):
+    """Return True if gerrit.host is set."""
+    if self.is_gerrit is None:
+      self.is_gerrit = bool(self._GetConfig('gerrit.host', False))
+    return self.is_gerrit
+
   def GetGerritSkipEnsureAuthenticated(self):
     """Return True if EnsureAuthenticated should not be done for Gerrit
     uploads."""
@@ -1323,9 +1329,10 @@
 
     remote, remote_branch = self.GetRemoteBranch()
     target_ref = GetTargetRef(remote, remote_branch, None)
-    args.extend(['--gerrit_url', self.GetCodereviewServer()])
-    args.extend(['--gerrit_project', self.GetGerritProject()])
-    args.extend(['--gerrit_branch', target_ref])
+    if settings.GetIsGerrit():
+      args.extend(['--gerrit_url', self.GetCodereviewServer()])
+      args.extend(['--gerrit_project', self.GetGerritProject()])
+      args.extend(['--gerrit_branch', target_ref])
 
     author = self.GetAuthor()
     issue = self.GetIssue()