Starting MUSIC with undefined application causes segmentation fault

[jakobj]

If an application has not config entry, as in the following:

stoptime=1.             
rtf=1.                  
[sender]                
  binary=./sender.py    
  np=1                  
sender.out->receiver.in 

music crashes with a segmentation fault:

Primary job  terminated normally, but 1 process returned
a non-zero exit code. Per user-direction, the job has been aborted.
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mpirun noticed that process rank 0 with PID 0 on node jordan exited on signal 11 (Segmentation fault).

It would be more helpful for the user to detect the broken config file and raise an exception in which the cause for the error is explained.