Resposta curta, você pode controlar isso com um sinalizador de linha de comando: -o 'StreamLocalBindUnlink=yes'
Resposta longa: Veja ssh_config (5):
StreamLocalBindUnlink
Specifies whether to remove an existing Unix-domain socket file for local or
remote port forwarding before creating a new one. If the socket file already
exists and StreamLocalBindUnlink is not enabled, ssh will be unable to forward
the port to the Unix-domain socket file. This option is only used for port for‐
warding to a Unix-domain socket file.
The argument must be yes or no (the default).