Adds rate limiting to the login page

app/pages/login.php

@@ -22,6 +22,7 @@ try {
     $dbWeb = connectDB($config);
 
     if ( $_SERVER['REQUEST_METHOD'] == 'POST' ) {
+        try {
             $username = $_POST['username'];
             $password = $_POST['password'];
 
@@ -66,6 +67,9 @@ try {
                 header('Location: ' . htmlspecialchars($app_root));
                 exit();
             }
+        } catch (Exception $e) {
+            $error = $e->getMessage();
+        }
     }
 } catch (Exception $e) {
     $error = getError('There was an unexpected error. Please try again.', $e->getMessage());