package/janus-gateway: add staging installation

Install janus to staging directory so that external plugins can be built.

Signed-off-by: Leo Soares <leojrfs@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit f80b393d4506783bb2d27d3d97730040857ec4e1)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/janus-gateway/janus-gateway.mk

@@ -10,6 +10,7 @@ JANUS_GATEWAY_LICENSE = GPL-3.0 with OpenSSL exception
 JANUS_GATEWAY_LICENSE_FILES = COPYING
 JANUS_GATEWAY_CPE_ID_VENDOR = meetecho
 JANUS_GATEWAY_CPE_ID_PRODUCT = janus
+JANUS_GATEWAY_INSTALL_STAGING = YES
 
 # ding-libs provides the ini_config library
 JANUS_GATEWAY_DEPENDENCIES = host-pkgconf jansson libnice \