fix is x11, on conn

Signed-off-by: dignow <linlong1265@gmail.com>

src/platform/linux.rs

@@ -35,6 +35,10 @@ type Xdo = *const c_void;
 pub const PA_SAMPLE_RATE: u32 = 48000;
 static mut UNMODIFIED: bool = true;
 
+lazy_static::lazy_static! {
+    pub static ref IS_X11: bool = hbb_common::platform::linux::is_x11_or_headless();
+}
+
 thread_local! {
     static XDO: RefCell<Xdo> = RefCell::new(unsafe { xdo_new(std::ptr::null()) });
     static DISPLAY: RefCell<*mut c_void> = RefCell::new(unsafe { XOpenDisplay(std::ptr::null())});
@@ -1360,3 +1364,8 @@ impl Drop for WallPaperRemover {
         }
     }
 }
+
+#[inline]
+pub fn is_x11() -> bool {
+    *IS_X11
+}