w32: Do no use Registry item DefaultLogFile for the main tools.

* g10/gpg.c (main): Set LOG_NO_REGISTRY.
* sm/gpgsm.c (main): Ditto.
* tools/gpg-connect-agent.c (main): Ditto.
* tools/gpgconf.c (main): Ditto.
(show_other_registry_entries): Print "DefaultLogFile".

The intention of this mostly forgotten registry entry was to allow for
easy debugging of the tools. However, with the global config
files (and in 2.3 with common.conf) things are anyway better. We
disable the use for the commonly used tools so that it does not look
like calling gpg on the command line seems to block with no output if
the log server (e.g. tcp://1.2.3.4:11111) is not reachable.