feat(s3 region): added configurable s3 region.

vcsserver/lib/archive_cache/backends/objectstore_cache.py

@@ -142,10 +142,13 b' class ObjectStoreCache(BaseCache):'
         endpoint_url = settings.pop('archive_cache.objectstore.url')
         key = settings.pop('archive_cache.objectstore.key')
         secret = settings.pop('archive_cache.objectstore.secret')
+        region = settings.pop('archive_cache.objectstore.region')
 
         log.debug('Initializing %s archival cache instance', self)
 
-        fs = fsspec.filesystem('s3', anon=False, endpoint_url=endpoint_url, key=key, secret=secret)
+        fs = fsspec.filesystem(
+            's3', anon=False, endpoint_url=endpoint_url, key=key, secret=secret, client_kwargs={'region_name': region}
+        )
 
         # init main bucket
         if not fs.exists(self._bucket):