Swiss. But the Avros will be gone in a couple of months and Swiss has begun replacing them with E190s opb Helvetic and will bring their owns CS100s to LCY sooner than later.
Other than that, it is nowadays only ACMI-operators like Cello, Jota and WDL that are the first point of call for scheduled airlines that need ad hoc capacity to replacetheir own metal. All the others airlines have long replaced the Avros with Embraers (BACF, Lufthansa, Alitalia/Azzura).