jvb: set JVB_TCP_MAPPED_PORT default value

Author: saghul

env.example

@@ -215,7 +215,7 @@ JVB_PORT=10000
 # TCP Fallback for Jitsi Videobridge for when UDP isn't available
 JVB_TCP_HARVESTER_DISABLED=true
 JVB_TCP_PORT=4443
-# JVB_TCP_MAPPED_PORT=4443
+JVB_TCP_MAPPED_PORT=4443
 
 # A comma separated list of APIs to enable when the JVB is started [default: none]
 # See https://github.com/jitsi/jitsi-videobridge/blob/master/doc/rest.md for more information