Fixed plugin to be compatible with 1.509.3 (BTW, this core has improper Killer invocation, just for custom cores)

Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>
Removed erroneous check on master.
It should be restored in order to report errors before starting of script execution.

Signed-off-by: Oleg Nenashev <nenashev@synopsys.com>