fix mac tray icon to use template icon, no need to know theme any more

src/platform/macos.rs

@@ -45,10 +45,15 @@ extern "C" {
         max: u32,
         numModes: *mut u32,
     ) -> BOOL;
+    fn majorVersion() -> u32;
     fn MacGetMode(display: u32, width: *mut u32, height: *mut u32) -> BOOL;
     fn MacSetMode(display: u32, width: u32, height: u32) -> BOOL;
 }
 
+pub fn major_version() -> u32 {
+    unsafe { majorVersion() }
+}
+
 pub fn is_process_trusted(prompt: bool) -> bool {
     unsafe {
         let value = if prompt { YES } else { NO };