configure.ac: fix problem with --enable-cephfs-java

The AS_IF used to cover java related checks via --enable-cephfs-java
didn't work correctly. Use a plain 'if/fi' instead to make sure this
section is only executed if --enable-cephfs-java is used.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
Merge branch 'wip-rpm-update'

Merges work around for odd AS_IF behaviour in configure.ac.