ovs-sandbox: Tell gdb to start the daemon.

ovs-sandbox: Tell gdb to start the daemon.

The current gdb support launches gdb but doesn't start the daemon.
If you start ovsdb-server with gdb, ovs-sandbox produces an error as
it tries to run ovs-vsctl before ovsdb-server is running.  Telling gdb
to start the daemon immediately avoids this error.

There are cases where it's useful to go straight to the gdb prompt,
too.  For example, someone may want to set a breakpoint.  In that
case, it's easy enough to just kill it, set a breakpoint, and execute
'run' again.

In passing, fix indentation to use spaces instead of tabs.

Signed-off-by: Russell Bryant <rbryant@redhat.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>