Fix avatar upload requiring username/email (Issue #12)

- Remove unnecessary wrapper form around Profile Picture section
- Avatar upload form is now standalone, not nested
- Prevents browser validation from requiring username/email when uploading avatar

Fixes #12

templates/settings_profile.html

@@ -243,7 +243,6 @@
             {% endwith %}
         </div>
 
-        <form method="POST">
         <div class="profile-section">
             <h2>Profile Picture</h2>
             <div class="profile-avatar">
@@ -267,7 +266,6 @@
                 </div>
             </div>
         </div>
-        </form>
 
         <form method="POST">
             <div class="profile-section">