title: Driver claims to not accept jdbcUrl, ${JDBC_DATABASE_URL} when setting externalized config
body: <p>I'm using the instructions in <a href="https://devcenter.heroku.com/articles/connecting-to-relational-databases-on-heroku-with-java#using-the-jdbc_database_url-in-a-spring-boot-app" rel="nofollow noreferrer">this Heroku article</a> to attempt to externalize database strings for a hosted Postgres DB. When I use the literal string, I can connect with no issues. However, when I attempt to use the externalized variable ${JDBC_DATABASE_URL}, I'm getting the error message:</p>
  <pre><code>2022-06-17 17:30:17.063  WARN 7712 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'liquibase' defined in class path resource [org/springframework/boot/autoconfigure/liquibase/LiquibaseAutoConfiguration$LiquibaseConfiguration.class]: Invocation of init method failed; nested exception is java.lang.RuntimeException: Driver org.postgresql.Driver claims to not accept jdbcUrl, ${JDBC_DATABASE_URL}
  </code></pre>
  <p>It looks like it's interpreting the externalized variable itself as a literal string, but I have no idea why. I haven't included any other config files because it is currently working with the database string, but I can attach them if need be. Any ideas?</p>