remove exploitdb-papers, distfile is just too big as pointed out

by sthen@, if you need it, install exploitdb, and extract the
tarball in /usr/local/share/exploitdb-papers and you're good to go

books/exploitdb-papers/Makefile

@@ -1,29 +0,0 @@
-# $OpenBSD: Makefile,v 1.1.1.1 2019/02/12 09:58:52 sebastia Exp $
-
-PKG_ARCH =	*
-
-COMMENT =	archive of public security related papers
-
-GH_ACCOUNT =	offensive-security
-GH_PROJECT =	exploitdb-papers
-GH_TAGNAME =	2019-02-02
-DISTNAME =	exploitdb-papers-${GH_TAGNAME}
-PKGNAME =	exploitdb-papers-${GH_TAGNAME:S,-,,g}
-
-CATEGORIES =	books
-
-MAINTAINER =	Sebastian Reitenbach <sebastia@openbsd.org>
-
-# GPLv2
-PERMIT_PACKAGE_CDROM =	Yes
-
-RUN_DEPENDS +=	security/exploitdb
-
-NO_BUILD =	Yes
-NO_TEST =	Yes
-
-do-install:
-	${INSTALL_DATA_DIR} ${PREFIX}/share
-	cp -R ${WRKSRC} ${PREFIX}/share/exploitdb-papers
-
-.include <bsd.port.mk>

books/exploitdb-papers/distinfo

@@ -1,2 +0,0 @@
-SHA256 (exploitdb-papers-2019-02-02.tar.gz) = QEZRVg9Godix4VWopnNN/gnHJ1JjDwLH0Q3pBK/+E48=
-SIZE (exploitdb-papers-2019-02-02.tar.gz) = 2299738799

books/exploitdb-papers/pkg/DESCR

@@ -1,7 +0,0 @@
-The Exploit Database is an archive of public exploits and corresponding
-vulnerable software, developed for use by penetration testers and
-vulnerability researchers. Its aim is to serve as the most comprehensive
-collection of exploits, shellcode and papers gathered through direct
-submissions, mailing lists, and other public sources, and present them
-in a freely-available and easy-to-navigate database. This is the
-papers section of it.