hedgewars-engine (rust): fix "protocol_version" -> "hedgewars_engine_protocol_version"
That function/symbol was renamed in ef2fc0210362
[package]
name = "physfs-rs"
version = "0.1.0"
license = "zlib"
authors = [ "Robert Habermeier" ]
[lib]
name = "physfs"
[dependencies]
libc = "0.1"