Add more retries when restoring a basebackup

Commit 4869d84 added logic to make the
number of retries dependent on the backup size. Instead of allowing for
one error every 64GB allow for one every 10GB.

It's better to retry more than to start from scratch when things
go wrong.

pghoard/restore.py

@@ -607,8 +607,8 @@ def _get_basebackup(
                 os.chmod(dirname, 0o700)
 
         # Based on limited samples, there could be one stalled download per 122GiB of transfer
-        # So we tolerate one stall for every 64GiB of transfer (or STALL_MIN_RETRIES for smaller backup)
-        stall_max_retries = max(STALL_MIN_RETRIES, int(int(metadata.get("total-size-enc", 0)) / (64 * 2 ** 30)))
+        # So we tolerate one stall for every 10GiB of transfer (or STALL_MIN_RETRIES for smaller backup)
+        stall_max_retries = max(STALL_MIN_RETRIES, int(int(metadata.get("total-size-enc", 0)) / (10 * 2 ** 30)))
 
         fetcher = BasebackupFetcher(
             app_config=self.config,