Sap Service Discovery Error Spam Fix

It looks like report_note no longer accepts a proto so the module spams the following error, also pointless begin end block cleared away.

```
[-] [2014.11.20-13:02:43] xxxxxxxxxxx:50013 exception ActiveRecord::RecordInvalid Validation failed: Proto is not included in the list ["/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/validations.rb:56:in `save!'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/attribute_methods/dirty.rb:33:in `save!'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/transactions.rb:264:in `block in save!'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/transactions.rb:313:in `block in with_transaction_returning_status'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/transactions.rb:208:in `transaction'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/transactions.rb:311:in `with_transaction_returning_status'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/transactions.rb:264:in `save!'", "/root/git/metasploit-framework/lib/msf/core/db_manager/service.rb:103:in `block in report_service'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/connection_adapters/abstract/connection_pool.rb:129:in `with_connection'", "/root/git/metasploit-framework/lib/msf/core/db_manager/service.rb:49:in `report_service'", "/root/git/metasploit-framework/lib/msf/core/db_manager/note.rb:96:in `block in report_note'", "/var/lib/gems/1.9.1/gems/activerecord-3.2.19/lib/active_record/connection_adapters/abstract/connection_pool.rb:129:in `with_connection'", "/root/git/metasploit-framework/lib/msf/core/db_manager/note.rb:57:in `report_note'", "/root/git/metasploit-framework/lib/msf/core/auxiliary/report.rb:125:in `report_note'", "/root/git/metasploit-framework/modules/auxiliary/scanner/sap/sap_service_discovery.rb:238:in `block (2 levels) in run_host'", "/root/git/metasploit-framework/lib/msf/core/thread_manager.rb:100:in `call'", "/root/git/metasploit-framework/lib/msf/core/thread_manager.rb:100:in `block in spawn'"]
```

## Verification
- [ ] Before, module spams errors when it finds a port open.
- [ ] After, module functions as expected