lets use the correct camel case

Author: jrushlow

src/Maker/MakeAuthenticator.php

@@ -283,7 +283,7 @@ private function generateAuthenticatorClass(array $securityData, string $authent
                 'user_class_name' => $userClassNameDetails->getShortName(),
                 'username_field' => $userNameField,
                 'username_field_label' => Str::asHumanWords($userNameField),
-                'username_field_var' => Str::asCamelCase($userNameField),
+                'username_field_var' => Str::asLowerCamelCase($userNameField),
                 'user_needs_encoder' => $this->userClassHasEncoder($securityData, $userClass),
                 'user_is_entity' => $this->doctrineHelper->isClassAMappedEntity($userClass),
                 'provider_key_type_hint' => $this->providerKeyTypeHint(),