If HAVE_LIBNLS is not defined, OS functions (iconv and Win32
native APIs) are used for character set conversion of command
line arguments.
Fix bug # 177766 - LDAP tools should reject second -h argument.
A second -p argument is also rejected.
Fix bug # 159139 - HP/UX: LDAP command line tools do no charset conversion.
Removed special case makefile rules for convutf8.cpp on HP/UX.