Merge branch '535-linux-perms-broken' into 'master'

Resolve "named is broken on linux due to user permissions"

Closes #535

See merge request isc-projects/bind9!783

bin/named/unix/os.c

@@ -488,6 +488,7 @@ void
 named_os_minprivs(void) {
 #if defined(HAVE_SYS_CAPABILITY_H)
 	linux_keepcaps();
+	named_os_changeuser();
 	linux_minprivs();
 #endif
 }