striping extra spaces if etcd.hosts is written as comma separated string
Patroni was failing to connect to the etcd server if config looks like following:
```yaml
etcd:
hosts: host1:port1, host2:port2
```
@@ -416,7 +416,7 @@ class Etcd(AbstractDCS):
config['hosts'] = []
for value in hosts:
if isinstance(value, six.string_types):
- config['hosts'].append(uri(protocol, split_host_port(value, default_port)))
+ config['hosts'].append(uri(protocol, split_host_port(value.strip(), default_port)))
elif 'host' in config:
host, port = split_host_port(config['host'], 2379)
config['host'] = host
