sysutils/apachetop: Clean up port

• Use DISTVERSION instead of PORTVERSION
• Use upstream release archive as recommended by Porters Handbook, this also removes the need to run USES= autoreconf
• Use GNU_CONFIGURE instead of HAS_CONFIGURE as this configure script uses GNU Autotools
• Use CONFIGURE_ENV to tell configure script where ncurses is located which makes patching unnecessary.

PR: 265932
Reviewed by: lukasz@wasikowski.net (maintainer)