package/janus-gateway: fix libogg dependency

package/janus-gateway: fix libogg dependency

libogg is not only used for voicemail plugin, it is an optional
dependency of:
- audiobridge plugin since version 0.9.3 and
  https://github.com/meetecho/janus-gateway/commit/53761d07c5456424d368c708fda2757e6606a4bf
- streaming plugin since version 0.9.3 and
  https://github.com/meetecho/janus-gateway/commit/d9aa1cec84c662f2f7fda025ee023f6dec927bdc

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>