Change :final metadata to @:final metadata

[Vortex2Oblivion]

No description provided.

[Simn]

I'm never sure about this because the actual metadata string is indeed :final, the @ just says "this is metadata". We had this problem with something like Compiler.addGlobalMetadata as well where users used the @, and I think we now support this.

[Vortex2Oblivion]

I'm never sure about this because the actual metadata string is indeed :final, the @ just says "this is metadata". We had this problem with something like Compiler.addGlobalMetadata as well where users used the @, and I think we now support this.

I made the pull request because, atleast to my knowledge, all the other documentations about metadata use @: and not :