Disable lto to fix build

It looks like that golang applications currently fails[1] to build
with lto enabled on CGO_CFLAGS/CGO_CXXFLAGS. Disabling lto until
there is a fix from upstream golang.

References
----------
[1] golang/go#43505

.SRCINFO

@@ -1,12 +1,13 @@
 pkgbase = xd-torrent
 	pkgdesc = An I2P BitTorrent client
 	pkgver = 0.4.2
-	pkgrel = 1
+	pkgrel = 2
 	url = https://xd-torrent.github.io/
 	arch = x86_64
 	license = MIT
 	makedepends = go
 	depends = glibc
+	options = !lto
 	backup = etc/xd.conf
 	source = https://github.com/majestrate/XD/archive/v0.4.2/xd-torrent-0.4.2.tar.gz
 	source = 010-xd-torrent-use-arch-ldflags.patch

PKGBUILD

@@ -2,7 +2,7 @@
 
 pkgname=xd-torrent
 pkgver=0.4.2
-pkgrel=1
+pkgrel=2
 pkgdesc='An I2P BitTorrent client'
 arch=('x86_64')
 url='https://xd-torrent.github.io/'
@@ -17,6 +17,7 @@ source=("https://github.com/majestrate/XD/archive/v${pkgver}/${pkgname}-${pkgver
         'xd-torrent.sysusers'
         'xd-torrent.tmpfiles'
         'xd.conf')
+options=('!lto')
 sha256sums=('77490f37ea979d559490611f874acbb618072e3685f15d7b6254bedfe31a0b03'
             '0eb00a6df35028549286fce92cb158d3c84ec49fad72e1e437de5b5e309719d2'
             '6b3d959b55623c3f907be0e1c53c7092e9328cb0b10c336102d012d716438a14'