Use strncpy() properly in general_option_edit()
Use strncpy() properly in general_option_edit()

Always use strncpy() to copy strings between fixed-size buffers and pass
the buffer size as maximal length parameter.

Signed-off-by: Lukas Fleischer <c9ca73f8336dcfb037ec2c2abf52d80a6847a5cd@calcurse.org>

lfos/calcurse,lfos/calcurse,lfos/calcurse