TurboGears: drop workaround for < 2.4

Backout a38e05a0c79e and tweak.

kallithea/lib/celerylib/__init__.py

@@ -101,11 +101,9 b' def __get_lockkey(func, *fargs, **fkwarg'
 def locked_task(func):
     def __wrapper(func, *fargs, **fkwargs):
         lockkey = __get_lockkey(func, *fargs, **fkwargs)
-        lockkey_path = config.get('cache_dir') or config['app_conf']['cache_dir']  # Backward compatibility for TurboGears < 2.4
-
         log.info('running task with lockkey %s', lockkey)
         try:
-            l = DaemonLock(os.path.join(lockkey_path, lockkey))
+            l = DaemonLock(os.path.join(config['cache_dir'], lockkey))
             ret = func(*fargs, **fkwargs)
             l.release()
             return ret

kallithea/model/async_tasks.py

@@ -84,12 +84,9 b' def get_commits_stats(repo_name, ts_min_'
     DBS = celerylib.get_session()
     lockkey = celerylib.__get_lockkey('get_commits_stats', repo_name, ts_min_y,
                             ts_max_y)
-    lockkey_path = config.get('cache_dir') or config['app_conf']['cache_dir']  # Backward compatibility for TurboGears < 2.4
-
     log.info('running task with lockkey %s', lockkey)
-
     try:
-        lock = celerylib.DaemonLock(os.path.join(lockkey_path, lockkey))
+        lock = celerylib.DaemonLock(os.path.join(config['cache_dir'], lockkey))
 
         co_day_auth_aggr = {}
         commits_by_day_aggregate = {}