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

It does not use any functions from libcap directly. The CAP_SYS_ADMIN constant
in use by this file comes from <linux/capability.h> imported through "missing.h".

Tested that "systemd-localed" builds cleanly and works after this change.

src/locale/localed.c

@@ -23,7 +23,6 @@
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
-#include <sys/capability.h>
 
 #include "sd-bus.h"