remove many unwrap and enum_value_or_default

Signed-off-by: 21pages <pages21@163.com>

src/common.rs

@@ -725,7 +725,7 @@ pub fn run_me<T: AsRef<std::ffi::OsStr>>(args: Vec<T>) -> std::io::Result<std::p
     }
     #[cfg(feature = "appimage")]
     {
-        let appdir = std::env::var("APPDIR").unwrap();
+        let appdir = std::env::var("APPDIR").map_err(|_| std::io::ErrorKind::Other)?;
         let appimage_cmd = std::path::Path::new(&appdir).join("AppRun");
         log::info!("path: {:?}", appimage_cmd);
         return std::process::Command::new(appimage_cmd).args(&args).spawn();