Fix pylint unused-* warnings in webkitpy/tool.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/commitannouncer.py

 # Copyright (c) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 11 matching lines @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import logging
 from optparse import make_option
 import time
 import traceback
 
 from webkitpy.common.config.irc import update_wait_seconds
-from webkitpy.tool.bot.commitannouncer import CommitAnnouncer
 from webkitpy.tool.bot.commitannouncer import CommitAnnouncerThread
 from webkitpy.tool.commands.command import Command
 
 _log = logging.getLogger(__name__)
 announce_path = "third_party/WebKit"
 
 
 class CommitAnnouncerCommand(Command):
     name = "commit-announcer"
     help_text = "Start an IRC bot for announcing new git commits."
     show_in_main_help = True
 
     def __init__(self):
         options = [
             make_option("--irc-password", default=None, help="Specify IRC password to use."),
         ]
         super(CommitAnnouncerCommand, self).__init__(options)
 
     def execute(self, options, args, tool):
         bot_thread = CommitAnnouncerThread(tool, announce_path, options.irc_password)
         bot_thread.start()
         _log.info("Bot started")
         try:
             while bot_thread.is_alive():
                 bot_thread.bot.post_new_commits()
                 time.sleep(update_wait_seconds)
         except KeyboardInterrupt:
             _log.error("Terminated by keyboard interrupt")
-        except Exception as e:
+        except Exception:
             _log.error("Unexpected error:")
             _log.error(traceback.format_exc())
 
         if bot_thread.is_alive():
             _log.info("Disconnecting bot")
             bot_thread.stop()
         else:
             _log.info("Bot offline")
         _log.info("Done")