Wrong call to kill when exiting PC Miner

[dimaguy]

Describe the bug
when sending sigint (ctrl-c) to PC_Miner
Terminated pi@raspberrypi:~/source/duino-coin $ /bin/sh: 1: kill: Usage: kill [-s sigspec | -signum | -sigspec] [pid | job]... or kill -l [exitstatus] /bin/sh: 1: kill: Usage: kill [-s sigspec | -signum | -sigspec] [pid | job]... or kill -l [exitstatus]

To Reproduce
Do the above in a linux terminal environment

Expected behavior
Mostly silent exit, preferably one where kill does it's job

System (please complete the following information):

• OS: latest Raspberry Pi OS
• Software: PC Miner
• Version: 3.4 (latest)