fix(server): correctly identify integers

mobile/openapi/lib/model/database_backup_config.dart

@@ -23,7 +23,7 @@ class DatabaseBackupConfig {
   bool enabled;
 
   /// Minimum value: 1
-  num keepLastAmount;
+  int keepLastAmount;
 
   @override
   bool operator ==(Object other) => identical(this, other) || other is DatabaseBackupConfig &&
@@ -60,7 +60,7 @@ class DatabaseBackupConfig {
       return DatabaseBackupConfig(
         cronExpression: mapValueOfType<String>(json, r'cronExpression')!,
         enabled: mapValueOfType<bool>(json, r'enabled')!,
-        keepLastAmount: num.parse('${json[r'keepLastAmount']}'),
+        keepLastAmount: mapValueOfType<int>(json, r'keepLastAmount')!,
       );
     }
     return null;