Sat launches and listens on a port even if the .wasm file doesn't exist

[danielledeleo]

Example:

$ sat asdfg
{"log_message":"(W) configured to use HTTP with no TLS","timestamp":"2022-05-20T19:02:15.492193716-04:00","level":2,"app":{"sat_version":"v0.1.3"}}
{"log_message":"(E) failed to start asdf worker: failed to reconcilePoolSize: failed to addThread more than numRetries: runnable returned OnChange error: failed to addInstance: failed to builder.New: failed to internals: failed to get ref ModuleBytes: failed to ReadFile for Wasm module: open asdf: no such file or directory","timestamp":"2022-05-20T19:02:15.492388897-04:00","level":1}

It should behave the same way that it already does when run with no arguments.