email plugin: Avoid strtok_r to tokenize input.

email plugin: Avoid strtok_r to tokenize input.

Coverity (wrongly) thinks that "type" might have been NULL (since its
first argument is non-NULL, this cannot happen). It has a point about
insufficient NULL-ness checks, though, as "tmp" may very well be NULL and
we're passing it to atoi() which will likely not take this well.

CID: 37988