WMS GetMap unhandled error for custom requestsConfigurationRules

[stefanocudini]

Description

In the case where a new requestsConfigurationRules rule defines custom headers, for example, to authenticate a WMS layer with API tokens.
The case where geoserver returns an exception in the body, causing an attempt to reload the WMS layer, is not handled.

This could cause an infinite loop of WMS layer reload attempts.

How to reproduce

If you need to call a WMS layer, causing a response exception, this can be simulated by calling a non-existent layer.
The layer must match the custom rules, adding custom headers like the following:

"requestsConfigurationRules": [
    {
      "urlPattern": "http://localhost/geoserver/wms.*",
      "headers": {
        "X-Custom-Header": "CustomTOKEN"
      }
    }
]

Expected Result
layer loading must be blocked

• Not browser related