Improve logging in case of exception in JcrUtils.getRepository()

Neither full stack traces nor suppressed exceptions are logged in https://github.com/apache/jackrabbit/blob/0f0807d25283b8786d800dcc41821443f43c2f82/jackrabbit-jcr-commons/src/main/java/org/apache/jackrabbit/commons/JcrUtils.java#L206 which makes it hard to debug issues.

Instead of manually constructing error messages one should rely on Throwable.printStacktrace()