upstream: fix missing initialization on ka_count field
flb_upstream_conn.ka_count is not initialized and can get
random values.
This can break out_forward when it get wrong information
that tells that connection is reused, but it's not and
out_forward thinks that handshake is already done.
@@ -141,6 +141,7 @@ static struct flb_upstream_conn *create_conn(struct flb_upstream *u)
#endif
conn->ts_created = time(NULL);
conn->ts_available = 0;
+ conn->ka_count = 0;
MK_EVENT_ZERO(&conn->event);
