do not catch SIGBUS either as per SIG35-C

This related to commit: 2bef62a7561ccca8509a4ceaaf471967c5737fb6
SIGBUS is also in the list of Signals that should not be caught. see:
https://www.securecoding.cert.org/confluence/display/seccode/SIG35-C.+Do+not+return+from+a+computational+exception+signal+handler