user/nextcloud-client: bump to 2.6.4

changelog https://github.com/nextcloud/desktop/releases/tag/v2.6.4

user/nextcloud-client/APKBUILD

 # Contributor: Leonardo Arena <rnalrd@alpinelinux.org>
 # Maintainer: Max Rees <maxcrees@me.com>
 pkgname=nextcloud-client
-pkgver=2.6.3
+pkgver=2.6.4
 pkgrel=0
 pkgdesc="Nextcloud desktop client"
 url="https://github.com/nextcloud/desktop"
@@ -42,6 +42,6 @@ package() {
 	EOF
 }
 
-sha512sums="ddeb8a32e0208bc415bf421cb3ce05713adb617fa78c0b5cb4d894c9e8d3499dcc495c115de3ea7abb0c402eef4bc64ede8c59a7f056acda47779096fedc8025  nextcloud-client-2.6.3.tar.gz
+sha512sums="849bf9bfa6a50342f6b58e805dc72ef342cb5f3e2e27d8f45d6a48759b1956dec194fb376b9a6b760df724f01eec3a22aadaa439f03e5166b1b2afb5454e40f1  nextcloud-client-2.6.4.tar.gz
 38dd89ca2bf67294187bb4d5c59cdf725ec3b502f23bf4a60210e85c66f6a7e00da0e0b41775bc138159bed300dc60a1f179d1d6ad3b7a27e1aadf4f0576f348  no-webengine.patch
 c14054e6dc228ca77a659371b3c151e0551477fce3a2678a54da4ba73adbcf972a78114c5649adc3dc813fb01b55bbb812620caac0bc0460519424c2caa6c81f  test-fix-include.patch"