Remove libc dependency + setlocale call

This is already taken care of in Cursive:
e2f79776a4

src/main.rs

@@ -42,7 +42,6 @@ use std::sync::Arc;
 
 use clap::{App, Arg};
 use cursive::traits::Identifiable;
-use std::ffi::CString;
 
 use librespot_core::authentication::Credentials;
 use librespot_core::cache::Cache;
@@ -127,9 +126,6 @@ struct UserDataInner {
 }
 
 fn main() {
-    let buf = CString::new("").unwrap();
-    unsafe { libc::setlocale(libc::LC_ALL, buf.as_ptr()) };
-
     let backends = {
         let backends: Vec<&str> = audio_backend::BACKENDS.iter().map(|b| b.0).collect();
         format!("Audio backends: {}", backends.join(", "))