trie: fix up gcc 8.2.1 armv7 off_t vs jg2_file_offset
trie: fix up gcc 8.2.1 armv7 off_t vs jg2_file_offset

We really don't want to use off_t in the trie struct if we can avoid it since with
alignment it adds 16 bytes per trie-entry.  Cast around warnings.
sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets,sartura/libwebsockets