Set SSH connection timeout at 10 seconds

This mirrors what was done in 24b7672, setting the connection timeout to
the same value as the keepalive timeout. This allows us to remove the
per-invocation timeouts currently being set in `fx serve-updates` and
`fx wait`, and centralizes the knowledge of acceptable SSH timeouts.

Bug: 21491
Change-Id: I531720f96cff9f46e84f1a1e159590f600ce841c
diff --git a/fuchsia/developer-keys/ b/fuchsia/developer-keys/
index e406bbe..de4a4a8 100755
--- a/fuchsia/developer-keys/
+++ b/fuchsia/developer-keys/
@@ -13,6 +13,7 @@
   ControlPersist yes
   ControlMaster auto
   ControlPath /tmp/fuchsia-$USER-%r@%h:%p
+  ConnectTimeout 10
   ServerAliveInterval 1
   ServerAliveCountMax 10
   LogLevel ERROR