fix failure on missing value that has default

src/setup/os.rs

@@ -11,8 +11,12 @@ use std::{
 #[serde(deny_unknown_fields)]
 pub struct Os {
 	pub alpine: Alpine,
+
+	#[serde(default)]
 	pub rpi: Rpi,
+
 	pub host: Host,
+
 	pub user: Vec<User>
 }
 
@@ -172,6 +176,15 @@ pub struct Rpi {
 	pub usercfg: String
 }
 
+impl Default for Rpi {
+	fn default() -> Self {
+		Self {
+			cmdline: default_cmdline(),
+			usercfg: default_usercfg()
+		}
+	}
+}
+
 fn default_hostname() -> String {
 	"alpi".into()
 }