Update OAuth2EndpointUtils.java

[MicahZheng]

getQueryParameters only get query parameter ，
getFormParameters only get form parameter

[jgrandja]

@MicahZheng I don't understand why this change is needed?

Did you find an issue? If so, please provide a minimal sample or test that reproduces the issue so I can look into it further.

[MicahZheng]

When the query parameters and form parameters are the same, the method getFormParameters will not get any parameters. And my partner gave me such parameters when requesting my interface, and the query parameters and form parameters are exactly the same. It does provide enough parameters. Maybe he should only put the form parameters, but I found that the method getQueryParameters and the method getFormParameters are not Just get the corresponding content like his name

[jgrandja]

@MicahZheng Sorry but I still don't understand your use case. As mentioned in the previous comment:

If so, please provide a minimal sample or test that reproduces the issue so I can look into it further.

This will help me understand your use case. As of now, I don't see any issues and this PR will get closed if you're unable to provide a reproducer.