[krbdev.mit.edu #4088] gss_import_name can fail to call gssint_initialize_library()

[Tom Yu via RT]

Paul Vixie reports that one of imapd's calls to gss_release_name()
following a successful gss_import_name() crashes due to an assertion
failure, which after my brief analysis results from a code path in
gss_import_name() failing to call through the gssint_get_mechanism()
choke point which calls gssint_initialize_library().