Fixes https://github.com/cryptomator/cryptomator/issues/887

Set text in password field to null when they get swiped

main/ui/src/main/java/org/cryptomator/ui/controls/SecPasswordField.java

@@ -249,6 +249,7 @@ public class SecPasswordField extends PasswordField {
 	public void swipe() {
 		swipe(content);
 		length = 0;
+		setText(null);
 	}
 
 	private void swipe(char[] buffer) {