[script] fix unbound variable in macOS (#5210)
[script] fix unbound variable in macOS (#5210)


srickardti/openthread,lanyuwen/openthread,lanyuwen/openthread,lanyuwen/openthread,jwhui/openthread,openthread/openthread,jwhui/openthread,bukepo/openthread,srickardti/openthread,openthread/openthread,chshu/openthread,bukepo/openthread,abtink/openthread,lanyuwen/openthread,openthread/openthread,srickardti/openthread,abtink/openthread,chshu/openthread,chshu/openthread,lanyuwen/openthread,srickardti/openthread,chshu/openthread,jwhui/openthread,jwhui/openthread,chshu/openthread,chshu/openthread,lanyuwen/openthread,openthread/openthread,bukepo/openthread,abtink/openthread,bukepo/openthread,abtink/openthread