Remove a ridiculous realloc call from torgzip.c

realloc()ing a thing in order to try to save memory on it just
doesn't make sense with today's allocators.  Instead, let's use the
fact that whenever we decompress something, either it isn't too big,
or we chop it up, or we reallocate it.

src/common/torgzip.c

@@ -213,10 +213,6 @@ tor_gzip_compress(char **out, size_t *out_len,
    *    the newly unsigned field isn't negative." */
   tor_assert(stream->total_out >= 0);
 #endif
-  if (((size_t)stream->total_out) > out_size + 4097) {
-    /* If we're wasting more than 4k, don't. */
-    *out = tor_realloc(*out, stream->total_out + 1);
-  }
   if (deflateEnd(stream)!=Z_OK) {
     log_warn(LD_BUG, "Error freeing gzip structures");
     goto err;