Misleading Message When Creating A New Lookup Table Cache

[ErrWare]

When I start a server with a new lookup table cache (e.q. liblisa-semantics-tool server --cache amd-7700x.cache semantics/amd-7700x.json) I get the following message:

Error reading "amd-7700x.cache": No such file or directory (os error 2)

As a user this makes me think:

1. Error? That's fatal, why is the process continuing?
2. The caching mechanism is broken.

Contrary to expectation, it's actually fine and the program will create the cache as it should. The message should either be skipped in the event of error number 2 (no such file) or replaced with something more representative like "Cache name not found, creating new cache..."

I think this is an easy fix to anyone familiar with rust. Just change the error message line in server.rs:250 to skip its output if the error message number is 2.

[jxors]

Thanks! I agree that the error message could be better here. My focus is currently elsewhere, but I'm happy to merge pull requests if you or someone else is able to work on this in the meantime.

[jxors]

Thank you for fixing this! (#4)