update deprecated instructions

[Geczy]

WARNING: This node will not work properly for concurrent executions. It will only throttle sequential executions. It is recommended to set N8N EXECUTIONS_PROCESS mode to "main", so all executions will be sequential.

1.27.0

What changed?

The execution mode own was removed.
If EXECUTIONS_PROCESS is set to main or if executions.process in a config file is set to main n8n will print a warning, but start up normally.
If EXECUTIONS_PROCESS is set to own or if executions.process in a config file is set to own n8n will print an error message and refuse to start up.

When is action necessary?

If you use own mode and need the isolation and performance gains, please consider using queue mode instead, otherwise switch to main mode by removing the environment variable or config field.
If you have the environment variable EXECUTIONS_PROCESS or the config field executions.process set, please remove them. The environment variable has no effect anymore and the configuration field will be removed in future releases, prevent n8n from starting if it is still set.