Fix a segmentation fault (double free actually) when using multiple databases as argument to start, stop or kill.
Fix a segmentation fault (double free actually) when using multiple databases as argument to start, stop or kill.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb