Target resync now flushes all buffers (caused errors before)

src/target.rs

@@ -37,6 +37,7 @@ impl PhysicalTarget {
 	}
 
 	pub fn resync_target(&mut self) -> Result<(), Error> {
+		self.port.discard_buffers()?;
 		self.port.set_dtr(true)?;
 		self.port.set_rts(true)?;
 		std::thread::sleep(Duration::from_millis(10));