[NTP] Revert change in PR 2598 (#4265)

We believe that the supervisord issue in face of clock rolling backwards
has been addressed. Therefore reverting change 2598 to allow ntp sync
to right clock at the start up time.

Signed-off-by: Ying Xie <ying.xie@microsoft.com>

build_debian.sh

@@ -273,10 +273,6 @@ sudo mv $FILESYSTEM_ROOT/grub-pc-bin*.deb $FILESYSTEM_ROOT/$PLATFORM_DIR/x86_64-
 ## Disable kexec supported reboot which was installed by default
 sudo sed -i 's/LOAD_KEXEC=true/LOAD_KEXEC=false/' $FILESYSTEM_ROOT/etc/default/kexec
 
-## Modifty ntp default configuration: disable initial jump (add -x), and disable
-## jump when time difference is greater than 1000 seconds (remove -g).
-sudo sed -i "s/NTPD_OPTS='-g'/NTPD_OPTS='-x'/" $FILESYSTEM_ROOT/etc/default/ntp
-
 ## Fix ping tools permission so non root user can directly use them
 ## Note: this is a workaround since aufs doesn't support extended attributes
 ## Ref: https://github.com/moby/moby/issues/5650#issuecomment-303499489