Style fixes.

Keep same ordering and simplify conditions.

src/zc/buildout/networkcache.py

@@ -62,8 +62,7 @@ def download_network_cached(dir_url, cache_url, path, url, logger, md5sum=None):
     if not LIBNETWORKCACHE_ENABLED:
         return False
 
-    if cache_url in (None, '',):
-        # Not able to use network cache
+    if not(dir_url and cache_url):
         return False
     if md5sum is None:
         md5sum = _get_md5_from_url(url)
@@ -95,14 +94,12 @@ def download_network_cached(dir_url, cache_url, path, url, logger, md5sum=None):
     return True
 
 
-def upload_network_cached(cache_url, dir_url, external_url, path, logger):
+def upload_network_cached(dir_url, cache_url, external_url, path, logger):
     """Upload file to a network cache server"""
     if not LIBNETWORKCACHE_ENABLED:
         return False
 
-    if cache_url in [None, ''] or dir_url in [None, '']:
-        logger.debug(
-             'Upload cache ignored, shacache or shadir was not provided!')
+    if not (dir_url and cache_url):
         return False
 
     file_name = external_url.split('/')[-1].split('#')[0].split('?')[0]