@typo in example-dnscrypt-proxy.toml (#628)

This can be can be useful… -> This can be useful…

dnscrypt-proxy/example-dnscrypt-proxy.toml

@@ -77,7 +77,7 @@ require_nofilter = true
 
 
 ## Always use TCP to connect to upstream servers.
-## This can be can be useful if you need to route everything through Tor.
+## This can be useful if you need to route everything through Tor.
 ## Otherwise, leave this to `false`, as it doesn't improve security
 ## (dnscrypt-proxy will always encrypt everything even using UDP), and can
 ## only increase latency.