irc.php: always print unhandled server responses
irc.php: always print unhandled server responses

Previously these were only printed in debug mode. This will help to
identify and trace issues in the production environment.

Since `readFromStream` now requires a bool return value, this change
also fixes the case of unhandled server responses not having a return
value in non-debug mode. Fixes the following error:

> Uncaught TypeError: readFromStream(): Return value must be of type bool, none returned

smrealms/smr,hemberger/smr,hemberger/smr,smrealms/smr,hemberger/smr,hemberger/smr,smrealms/smr