Stopping event generation for non-valid phase-space setup

[Juergen Reuter]

If a sqrts setting is too low or absent, but event generation is demanded (at least with gfortran) a segmentation fault is issued:

| Loading process library 'processes'
| Process 'eemm': keeping previous configuration
| Process 'eemma': keeping previous configuration
| Integrating process 'eemm'
| Generating phase space, writing file 'eemm.phs' (this may take a while)
*** Error: Phase space vanishes (sqrts must be positive)
*** Error: Process 'eemm': no valid phase-space channels found
*** Error: Process 'eemm': phase space setup failed, skipped
n_events =           10
| No analysis setup has been provided.
| Generating 10 events ...
Segmentation fault

[Juergen Reuter]

File showing the test case.

[kilian]

Error was in the inquiry functions for the integration results, fixed in [1446].

[Juergen Reuter]

Milestone v2.0.0final deleted