starter: Do not close all file descriptors after fork()

As we use libstrongswan and expect that it still works after the fork, we
can't just closefrom() all file descriptors. Watcher, for example, uses
a pipe to notify FDSET changes, which must be kept open.

Reverts 652ddf5ce2.

src/starter/starter.c

@@ -612,7 +612,6 @@ int main (int argc, char **argv)
 				int fnull;
 
 				close_log();
-				closefrom(3);
 
 				fnull = open("/dev/null", O_RDWR);
 				if (fnull >= 0)