Fixed MacOS build.

Cargo.toml

@@ -16,7 +16,6 @@ toml = "0.5.8"
 simple_logger = "1.11.0"
 rust-crypto = "^0.2"
 num_cpus = "1.13.0"
-thread-priority = "0.2.1"
 byteorder = "1.3.2"
 web-view = { version = "0.7.2", features = [] }
 tinyfiledialogs = "3.3.10"
@@ -38,6 +37,9 @@ derive_more = "0.99.9"
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3.7", features = ["impl-default", "wincon"]}
 
+[target.'cfg(not(macos))'.dependencies]
+thread-priority = "0.2.1"
+
 [build-dependencies]
 winres = "0.1"