utils/ipc-ssltunnel: Initialize global variables

utils/ipc-ssltunnel: Initialize global variables

In ipc-ssltunnel, global variables are used to store the topics and
hooks that are passed to ipc-tap and ipc-inject. These variables are
declared in main(), however not all of them are initialized. While
this is not a bug, the function should either initialize all of the
arrays or none at all.

This commit modifies ipc-ssltunnel to initialize all of the arrays
in main().