haproxy: add conflict to packages with SSL or without SSL support

haproxy: add conflict to packages with SSL or without SSL support

Both packages provide the same packages and should conflict to each
other.

Fixes:
```
Packages 'haproxy' and 'haproxy-nossl' do not conflict while providing same file: /usr/sbin/haproxy
Packages 'haproxy' and 'haproxy-nossl' do not conflict while providing same file: /etc/haproxy.cfg
Packages 'haproxy' and 'haproxy-nossl' do not conflict while providing same file: /etc/init.d/haproxy
```

They should not be installed side by side.

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>