bus: remove spurious include of <sys/capability.h>

They do not use any functions from libcap directly. The CAP_SYS_ADMIN constant
in use by bus-objects.c comes from <linux/capability.h> imported through
"missing.h". The "missing.h" header is imported through "util.h" which gets
imported in "bus-util.h".

Tested that everything builds cleanly after this change.

src/libsystemd/sd-bus/bus-objects.c

@@ -19,8 +19,6 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <sys/capability.h>
-
 #include "strv.h"
 #include "set.h"
 #include "bus-internal.h"

src/libsystemd/sd-bus/bus-util.c

@@ -20,7 +20,6 @@
 ***/
 
 #include <sys/socket.h>
-#include <sys/capability.h>
 
 #include "systemd/sd-daemon.h"