'Template not found' sticky even after creation of .gsp file till application restart.

### Steps to Reproduce

in development mode

1. call somewhere on existing page without creating _newTemplate.gsp
2. run code - 'Template not found' will arise
3. create relevant _newTemplate.gsp
4. run code again - 'Template not found' is sticky

### Expected Behaviour

After creation of template file template should be compiled and rendered.

### Actual Behaviour

Error of non-existing template is sticky till restart of application. That's VERY annoying

### Environment Information

- **Operating System**: Linux
- **Grails Version:** 3.3
- **JDK Version:** 1.8
- **Container Version (If Applicable):** TODO

### Example Application

error situation is dynamic, so hard to prepare sample

Reproduce the issue in development mode using the entry point and the _newTemplate.gsp file. Trace how the missing-template result persists after the file is created; done means the newly created template compiles and renders without restarting the application.

Written by the indexing model from the issue text.