fix: use correct env variable for invoice ninja password

Author: ershisan99

app/Models/Service.php

@@ -369,15 +369,15 @@ public function extraFields()
                     $email = $this->environment_variables()->where('key', 'IN_USER_EMAIL')->first();
                     $data = $data->merge([
                         'Email' => [
-                            'key' => 'IN_USER_EMAIL',
+                            'key' => data_get($email, 'key'),
                             'value' => data_get($email, 'value'),
                             'rules' => 'required|email',
                         ],
                     ]);
                     $password = $this->environment_variables()->where('key', 'SERVICE_PASSWORD_INVOICENINJAUSER')->first();
                     $data = $data->merge([
                         'Password' => [
-                            'key' => 'IN_PASSWORD',
+                            'key' => data_get($password, 'key'),
                             'value' => data_get($password, 'value'),
                             'rules' => 'required',
                             'isPassword' => true,