Incomplete prototype

The prototype for ub_event_get_version() in util/ub_event.h is missing
an argument list. C11 allows function definitions to have empty
argument lists but not prototypes. Patch relative to tip of svn tree:

Index: util/ub_event.h

Hi Dag-Erling,

Yes that is wrong. I fixed the incomplete prototypes for those
functions. Thanks for the report, this makes the code more
standards-compliant.

Best regards, Wouter