Seems bootstrapmain() never called find_my_exec(), and therefor never
manged to fill in the path to the timezone directory. With the new
timezone code that actully picks up a decent timezone on my system, that
causes initdb to fail because it can't find any acceptable timezone at
all.
This patch adds the required call to bootstrapmain(), and initdb works
again for me. Code itself directly copied from postgresmain().
//Magnus
