Fix nuke button prompt (#469)

Hitting the cancel button does not return "", but null. Therefore
the toLowerCase() fails, and throwing an exception means "sure go
ahead submitting this" to JS for some godforsaken reason.

Just remove the toLowerCase for now, have people type the names
properly.

nyaa/templates/user.html

@@ -123,7 +123,7 @@
 					</form>
 					{% if g.user.is_superadmin %}
 					<hr>
-					<form method="POST" onsubmit="return prompt('Please type {{ user.username }} to confirm').toLowerCase() == '{{ user.username }}'.toLowerCase()">
+					<form method="POST" onsubmit="return prompt('Please type {{ user.username }} to confirm') == '{{ user.username }}'">
 						{{ nuke_form.csrf_token }}
 						<div class="row">
 							<div class="col-md-6 text-left">