Wrong message clicking on craftSign on craft piloted by different player #587

Describe the bug
The title says it all, think there is a bug with the logic because I remembered there being a specific message for that.

To Reproduce
Steps to reproduce the behavior:

1. Have someone else pilot a craft for you
2. Try to click on their craft sign
3. "You are already commanding a craft!"

Expected behavior
The message should say something else, maybe something like a generic "Craft is already commanded!" or a more specific "Someone else is commanding this craft!"

Versions (please complete the following information):

• Movecraft: [8.0.0 Beta 1]
• Addons: [Not sure if this matters]
• Java [JDK 16]
• Minecraft 1.16.5

Additional context
This should probably be on the backburner but I'm writing this down so we are aware of this issue.