[toranj] fix the check for router entry "is link established" (#4566)
[toranj] fix the check for router entry "is link established" (#4566)


openthread/openthread,abtink/openthread,librasungirl/openthread,srickardti/openthread,lanyuwen/openthread,lanyuwen/openthread,jwhui/openthread,lanyuwen/openthread,lanyuwen/openthread,jwhui/openthread,librasungirl/openthread,bukepo/openthread,srickardti/openthread,lanyuwen/openthread,abtink/openthread,openthread/openthread,librasungirl/openthread,chshu/openthread,bukepo/openthread,chshu/openthread,abtink/openthread,bukepo/openthread,srickardti/openthread,openthread/openthread,jwhui/openthread,chshu/openthread,srickardti/openthread,chshu/openthread,librasungirl/openthread,chshu/openthread,lanyuwen/openthread,abtink/openthread,jwhui/openthread,openthread/openthread,bukepo/openthread,chshu/openthread