fix sync displays info && select monitor menu

Signed-off-by: fufesou <shuanglongchen@yeah.net>

src/common.rs

@@ -37,6 +37,8 @@ pub type NotifyMessageBox = fn(String, String, String, String) -> dyn Future<Out
 pub const CLIPBOARD_NAME: &'static str = "clipboard";
 pub const CLIPBOARD_INTERVAL: u64 = 333;
 
+pub const SYNC_PEER_INFO_DISPLAYS: i32 = 1;
+
 // the executable name of the portable version
 pub const PORTABLE_APPNAME_RUNTIME_ENV_KEY: &str = "RUSTDESK_APPNAME";