revert "fix unable to login if bad btUsername cookie"

fixes #112 Log Out is broken

src/login.php

@@ -67,31 +67,6 @@
 			$fail = false;
 			echo "
 				<script type='text/javascript'>
-					// Fakhruddin Ujjainwala, CC BY-SA 4.0, https://stackoverflow.com/a/24103596/3480193
-					function setCookie(name,value,days) {
-						var expires = \"\";
-						if (days) {
-							var date = new Date();
-							date.setTime(date.getTime() + (days*24*60*60*1000));
-							expires = \"; expires=\" + date.toUTCString();
-						}
-						document.cookie = name + \"=\" + (value || \"\")  + expires + \"; path=/\";
-					}
-
-					// When logging in, we need to overwrite any existing cookies, to prevent a bug where you can't log in if you got disabled while logged in.
-					// You can't set cookies in PHP after you've written any output.
-					// Therefore, we'll do it in JavaScript.
-					setCookie(
-						'btUsername',
-						'" . $_SESSION['btUsername'] . "',
-						'" . $COOKIE_EXP_TIME . "'
-					);
-					setCookie(
-						'btPassword',
-						'" . $_SESSION['btPassword'] . "',
-						'" . $COOKIE_EXP_TIME . "'
-					);
-
 					window.location = 'members/';
 				</script>
 			";