config parser: do not assume that realloc return same pointer

config parser: do not assume that realloc return same pointer

We need to update the parser->line pointer on realloc and do not
initialize the token array til after the potensial realloc in
bb_get_chunk_with_continuation().

While here, also replace a realloc() with malloc() where pointer always
is NULL.

Signed-off-by: Natanael Copa <natanael.copa@gmail.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>