Fix gen_wc8bit support for finding a UTF8 locale on host.

Fix gen_wc8bit support for finding a UTF8 locale on host.

gen_wc8bit was previously patched to support UTF8 locales other than the
default en_US.UTF-8 by patch id 0e14b8f425c562749d3821a42414b1ce6b3b0923.

This was incomplete in its implementation and still failed where item(s)
in the list returned by 'locale -a' already had 'UTF8' appended to the
name. This patch rectifies this situation, plus adds an extra fix to
avoid trimming '\n' from an empty line which could cause a segfault.

Signed-off-by: Andy Gibbs <andyg1001@hotmail.co.uk>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>