community/xterm: build with --enable-block-select

XTerm 397 added support for selecting a rectangular block of text
(https://invisible-island.net/xterm/xterm.log.html#xterm_397).

I have, since then, tested the patch on all versions up through 401, and
found no problems. Though it is a little crude, it is a welcome feature.

This is already included, all we need is to enable the build flag as I
have done here with `--enable-block-select`.

community/xterm/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: Simon Rupf <simon@rupf.net>
 pkgname=xterm
 pkgver=401
-pkgrel=0
+pkgrel=1
 pkgdesc="X Terminal Emulator"
 options="!check" # Requires vttest
 url="https://invisible-island.net/xterm"
@@ -51,6 +51,7 @@ build() {
 		--enable-narrowproto \
 		--enable-exec-xterm \
 		--enable-sixel-graphics \
+		--enable-block-select \
 		--with-tty-group=tty \
 		--with-utempter
 	make