use --ssh when reconnecting

[hxtmdev]

Reconnects did not use the --ssh args which can lead to using paramiko and/or missing options.

In my case it prompted for a password on reconnect even though there was a perfectly fine key just waiting to be used.

Reproduce:

• set up ssh with pubkey
• xpra --ssh=... start
• wait until connected
• kill ssh process to trigger reconnect (also caused by wifi problems)
• observe password prompt (not anymore with this patch)

[totaam]

Thanks!