Alter visibility of JdbcConfiguration to support better extensibility [DATAJDBC-288]

[spring-projects-issues]

Greg Turnquist opened DATAJDBC-288 and commented

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Referenced from: pull request #100

[spring-projects-issues]

Greg Turnquist commented

Jens Schauder What are you odds we could backport this patch? Dave would probably appreciate it

[spring-projects-issues]

Jens Schauder commented

My understanding was that the issue was solved/is going to get solved by spring-projects/spring-boot#15097