No ctrl+c possible when no data received

[andimik]

Similar to #25

$ odr-dabmod zmq+tcp://10.0.0.137  -f /tmp/test.raw
ODR-DabMod version v2.6.0-6-g6188ba9, compiled at Dec 31 2022, 12:48:41
Compiled with features: zeromq output_soapysdr SSE 
Input
  Type: zeromq
  Source: zmq+tcp://10.0.0.137
Output
  Name: /tmp/test.raw
  Sampling rate: 2.0480 MHz
2023-09-10Z13:53:31       Configuration parsed. Starting up version v2.6.0-6-g6188ba9
2023-09-10Z13:53:31       Setting up timestamp decoder with 0 offset
2023-09-10Z13:53:31       Input ZeroMQ: Receiving from tcp://10.0.0.137
2023-09-10Z13:53:31 ERROR Failed to connect ZeroMQ socket to 'tcp://10.0.0.137': 'Invalid argument'
2023-09-10Z13:53:31       ZeroMQ input worker terminated
^C^C^C^C^C^C^C^C^C^C^C^C^C^C^C

It works as soon as data are received, but if - for example - the IP Address was wrong, you cannot stop it.