Fixed loginname requirement description on user admin page

uffd/user/templates/user/show.html

@@ -51,7 +51,7 @@
 				<label for="user-loginname">{{_("Login Name")}}</label>
 				<input type="text" class="form-control" id="user-loginname" name="loginname" value="{{ user.loginname or '' }}" {% if user.uid %}readonly{% endif %}>
 				<small class="form-text text-muted">
-					{{_("Only letters, numbers and underscore (\"_\") are allowed. At most 32, at least 2 characters. There is a word blacklist. Must be unique.")}}
+					{{_("Only letters, numbers, dashes (\"-\") and underscores (\"_\") are allowed. At most 32, at least 2 characters. There is a word blacklist. Must be unique.")}}
 				</small>
 			</div>
 			{% if not user.uid %}