updated heartbleed module

-) Heartbeat length was added twice
-) Use the current date for the TLS client_hello

# Steps to verify
Compare the client_hello and heartbeat requests in wireshark.

## before
### client_hello
![image](https://cloud.githubusercontent.com/assets/105281/2652818/e39c8a52-bfb7-11e3-9aaa-62bb80684e82.png)

### heartbeat:
![image](https://cloud.githubusercontent.com/assets/105281/2652822/f3fdb7a4-bfb7-11e3-8566-b4b0d38a36d5.png)

## after
### client_hello
![image](https://cloud.githubusercontent.com/assets/105281/2652809/a2b5599c-bfb7-11e3-8d6a-b9050659ce49.png)

### heartbeat
![image](https://cloud.githubusercontent.com/assets/105281/2652813/b8a437be-bfb7-11e3-89e7-425a1a71a082.png)