unbound: Install auto-trust-anchor-file in /var/lib/unbound

This matches Debian and Ubuntu.

It does not take any effect yet, as we configure the path in the
configuration file installed by mxtools.

unbound.be0

@@ -58,7 +58,7 @@ mee_configure() {
         --disable-static \
         --enable-systemd \
         --with-pidfile="/run/unbound.pid" \
-        --with-rootkey-file="/var/unbound/root.key"
+        --with-rootkey-file="/var/lib/unbound/root.key"
 }
 
 mee_build() {
@@ -75,9 +75,9 @@ mee_build() {
 mee_install_post() {
     start_cmd mv ${D}/etc/unbound/unbound.conf{,.sample}
     start_cmd install -m 644 -D -t ${D}/lib/systemd/system ${B}/contrib/unbound.{service,socket}
-    start_cmd sed -i '/^ReadWritePaths=/ s,$, /var/unbound,' ${B}/contrib/unbound.service
+    start_cmd sed -i '/^ReadWritePaths=/ s,$, /var/lib/unbound,' ${B}/contrib/unbound.service
 
-    start_cmd install -o unbound -m 755 -d ${D}/var/unbound
+    start_cmd install -o unbound -m 755 -d ${D}/var/lib/unbound
 }
 
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