Adding workaround for apt not respecting pinning on the fly.

scripts/build/lb_chroot_apt

@@ -133,6 +133,14 @@ case "${1}" in
 			esac
 		fi
 
+		# Rebuild apt indices from scratch.
+		# Due to the fact that apt doesn't understand pinning on the
+		# fly, we need to manuall remove the cached indices and fetch
+		# them again.
+		rm -f chroot/var/cache/apt/* > /dev/null 2>&1 || true
+		rm -f chroot/var/lib/apt/lists/* > /dev/null 2>&1 || true
+		Chroot chroot "apt-get ${APT_OPTIONS} update"
+
 		# Creating stage file
 		Create_stagefile .stage/chroot_apt
 		;;