Remove redundant class member initialization in UpdateClient.

This has been detected by the static analyzer in another CL.

Change-Id: Ia10576bb78429ffd979dbe9ea262960ee823d497
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2310432Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790480}

components/update_client/update_client.cc

@@ -65,8 +65,7 @@ UpdateClientImpl::UpdateClientImpl(
     scoped_refptr<PingManager> ping_manager,
     UpdateChecker::Factory update_checker_factory,
     CrxDownloader::Factory crx_downloader_factory)
-    : is_stopped_(false),
-      config_(config),
+    : config_(config),
       ping_manager_(ping_manager),
       update_engine_(base::MakeRefCounted<UpdateEngine>(
           config,