[BUG] php-symfony generator bug, integer->maximum property

Created by: reznikartem

Bug Report Checklist

• [+] Have you provided a full/minimal spec to reproduce the issue?
• [+] Have you validated the input using an OpenAPI validator (example)?
• [4.0.0-beta3] What's the version of OpenAPI Generator used?
• [+] Have you search for related issues/PRs?

Hello. You have a bug in openapi-generator/modules/openapi-generator/src/main/resources/php-symfony/api_input_validation.mustache

In line 68 - 75 you have this code:

{{#maximum}} {{#exclusiveMaximum}} $asserts[] = new Assert\LessThan({{minimum}}); {{/exclusiveMaximum}} {{^exclusiveMaximum}} $asserts[] = new Assert\LessThanOrEqual({{minimum}}); {{/exclusiveMaximum}} {{/maximum}}

Variable minimum used here instead of maximum