Merge pull request #477 from bam80/patch-1

README.md: fix ASCII graphic offset

contrib/sni-router/README.md

     SNI match    │           │  default
                  v           v
            ┌─────────┐  ┌─────────┐
-           │   mtg    │  │  Caddy  │
-           │ :3128    │  │ :8443   │
-           │ FakeTLS  │  │ real TLS│
+           │   mtg   │  │  Caddy  │
+           │ :3128   │  │ :8443   │
+           │ FakeTLS │  │ real TLS│
            └─────────┘  └─────────┘
 ```