Fix glob memory leak in GSS initialization

In loadConfigFiles, call globfree even if glob fails, since glob can
allocate memory and report partial results on failure.  Also
initialize globbuf before calling glob; this is not strictly required,
but hedges against hypothetical libc implementation bugs which could
leave globbuf.gl_pathc or globbuf.gl_pathv uninitialized on error.

ticket: 7981
Disallow unlocked iteration of hash databases

It's not clear whether unlocked iteration over a hash DB2 database
will omit unaffected entries if database additions or deletions occur
concurrently with the iteration.  Avoid this situation by disabling
unlocked iteration in the unlikely event that someone is still using a
hash database for their KDB.

ticket: 7977