misc: fix handling boolean values

Fixes: https://github.com/jitsi/docker-jitsi-meet/issues/30

jigasi/rootfs/defaults/sip-communicator.properties

@@ -92,7 +92,7 @@ org.jitsi.jigasi.BREWERY_ENABLED=true
 
 org.jitsi.jigasi.xmpp.acc.IS_SERVER_OVERRIDDEN=true
 org.jitsi.jigasi.xmpp.acc.SERVER_ADDRESS={{ .Env.XMPP_SERVER }}
-{{ if .Env.ENABLE_AUTH }}
+{{ if .Env.ENABLE_AUTH | default "0" | toBool }}
 org.jitsi.jigasi.xmpp.acc.USER_ID={{ .Env.JIGASI_XMPP_USER }}@{{ .Env.XMPP_AUTH_DOMAIN }}
 org.jitsi.jigasi.xmpp.acc.PASS={{ .Env.JIGASI_XMPP_PASSWORD }}
 org.jitsi.jigasi.xmpp.acc.ANONYMOUS_AUTH=false