fix short argument

Author: lazytiger

README.md

@@ -49,11 +49,11 @@ USAGE:
     trojan proxy --hostname <hostname>
 
 FLAGS:
-        --help       Prints help information
+    -h, --help       Prints help information
     -V, --version    Prints version information
 
 OPTIONS:
-    -h, --hostname <hostname>    trojan server hostname
+    -H, --hostname <hostname>    trojan server hostname
 
 hoping@HopingPC:~/workspace/trojan-rs$ trojan help server
 trojan-server

src/config.rs

@@ -57,7 +57,7 @@ pub enum Mode {
 
 #[derive(Clap)]
 pub struct ProxyArgs {
-    #[clap(short, long, help = "trojan server hostname")]
+    #[clap(short = "H", long, help = "trojan server hostname")]
     pub hostname: String,
 }