identify user by username as well

views/login/login.php

@@ -4,7 +4,7 @@
     <h2>Login</h2>
     <div class="box">
         <form id="loginForm" action="/login" method="post" data-redirect-on-success="<?= $redirectUrl ?>">
-            <input type="email" class="text big fullWidth" name="email" placeholder="Email address" autocomplete="username" required autofocus>
+            <input type="email" class="text big fullWidth" name="email" placeholder="Email address / username" autocomplete="username" required autofocus>
             <input type="password" class="text big fullWidth marginTop" name="password" placeholder="Password" autocomplete="current-password" required minlength="6">
             <p id="loginFormError" class="formError justify marginTop"></p>
             <div class="right marginTop">