MEDIUM: quic: Make sure we return the tasklet from quic_accept_run

In quic_accept_run, return the tasklet to tell the scheduler the tasklet
is still alive, it is not yet needed, but will be soon.

src/quic_sock.c

@@ -1113,7 +1113,7 @@ struct task *quic_accept_run(struct task *t, void *ctx, unsigned int i)
 		}
 	}
 
-	return NULL;
+	return t;
 }
 
 /* Returns the maximum number of QUIC connections waiting for handshake to