docs: fix static clustering example

When using very similar flags to our examples, the cluster doesn't bootstrap due to mismatched protocols (`http` vs `https`) in the `-initial-advertise-peer-urls` and `initial-cluster` list:

```
./etcd -name infra0 -initial-advertise-peer-urls https://127.0.0.1:2380 \
>   -listen-peer-urls https://127.0.0.1:2380 \
>   -initial-cluster-token etcd-cluster-1 \
>   -initial-cluster infra0=http://127.0.0.1:2380,infra1=http://127.0.0.1:2381,infra2=http://127.0.0.1:2382 \
>   -initial-cluster-state new
2015/01/29 10:32:16 no data-dir provided, using default data-dir ./infra0.etcd
2015/01/29 10:32:16 etcd: listening for peers on https://127.0.0.1:2380
2015/01/29 10:32:16 etcd: listening for client requests on http://localhost:2379
2015/01/29 10:32:16 etcd: listening for client requests on http://localhost:4001
2015/01/29 10:32:16 etcd: stopping listening for client requests on http://localhost:4001
2015/01/29 10:32:16 etcd: stopping listening for client requests on http://localhost:2379
2015/01/29 10:32:16 etcd: stopping listening for peers on https://127.0.0.1:2380
2015/01/29 10:32:16 etcd: infra0 has different advertised URLs in the cluster and advertised peer URLs list
```

Documentation/clustering.md

@@ -39,22 +39,22 @@ If you are spinning up multiple clusters (or creating and destroying a single cl
 On each machine you would start etcd with these flags:
 
 ```
-$ etcd -name infra0 -initial-advertise-peer-urls https://10.0.1.10:2380 \
-  -listen-peer-urls https://10.0.1.10:2380 \
+$ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
+  -listen-peer-urls http://10.0.1.10:2380 \
   -initial-cluster-token etcd-cluster-1 \
   -initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
   -initial-cluster-state new
 ```
 ```
-$ etcd -name infra1 -initial-advertise-peer-urls https://10.0.1.11:2380 \
-  -listen-peer-urls https://10.0.1.11:2380 \
+$ etcd -name infra1 -initial-advertise-peer-urls http://10.0.1.11:2380 \
+  -listen-peer-urls http://10.0.1.11:2380 \
   -initial-cluster-token etcd-cluster-1 \
   -initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
   -initial-cluster-state new
 ```
 ```
-$ etcd -name infra2 -initial-advertise-peer-urls https://10.0.1.12:2380 \
-  -listen-peer-urls https://10.0.1.12:2380 \
+$ etcd -name infra2 -initial-advertise-peer-urls http://10.0.1.12:2380 \
+  -listen-peer-urls http://10.0.1.12:2380 \
   -initial-cluster-token etcd-cluster-1 \
   -initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
   -initial-cluster-state new