libostree: bump to version 2017.15

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libostree/libostree.hash

@@ -1,3 +1,3 @@
 # Locally calculated
-sha256 cab4782a7ab1c4d7ab8e390372788b73a7f83d9284418ba36a42b60cbc67851e  libostree-2017.14.tar.xz
+sha256 564b46c83373ea35f44eb39e62c6f6c876c8f2649aa30124b3f87282d2175138  libostree-2017.15.tar.xz
 sha256 b7993225104d90ddd8024fd838faf300bea5e83d91203eab98e29512acebd69c  COPYING

package/libostree/libostree.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBOSTREE_VERSION = 2017.14
+LIBOSTREE_VERSION = 2017.15
 LIBOSTREE_SOURCE = libostree-$(LIBOSTREE_VERSION).tar.xz
 LIBOSTREE_SITE = https://github.com/ostreedev/ostree/releases/download/v$(LIBOSTREE_VERSION)