Update docbook/wsug_src/*.txt using tools/update-tools-help.py. This
removes a lot of unwanted behavior that came with updating via a CMake
target.
Change-Id: I0a24f425e9673ef7bd074210d7047654c6755e79
Reviewed-on: https://code.wireshark.org/review/29416
Reviewed-by: Gerald Combs <gerald@wireshark.org>