remove unnecessary parameter expansion, as these are passed in to the service

chaperone.d/shapeshifter-dispatcher.conf

 shapeshifter-dispatcher.service: {
-     command: "/bin/sh -c 'exec /usr/local/bin/shapeshifter-dispatcher -transparent -server -state /srv/leap/shapeshifter-state -orport ${RHOST:-127.0.0.1}:${RPORT:-1194} -transports obfs4 -bindaddr obfs4-${LHOST}:${OBFSPORT:-23042} -logLevel ${LOGLEVEL:-WARN} -enableLogging -extorport ${RHOST:-127.0.0.1}:${EXTORPORT:-3334}'",
+     command: "/bin/sh -c 'exec /usr/local/bin/shapeshifter-dispatcher -transparent -server -state /srv/leap/shapeshifter-state -orport ${RHOST}:${RPORT} -transports obfs4 -bindaddr obfs4-${LHOST}:${OBFSPORT} -logLevel ${LOGLEVEL} -enableLogging -extorport ${RHOST}:${EXTORPORT}'",
      exit_kills: true
 }