fix the wrong api-ref location

The api documentation is now changed.
Update all links that are changed to the
right location.

Change-Id: I5df2cc540ae53f7f94d88ad2da90209f08c6faf3
Signed-off-by: song baisen <songbaisen@szzt.com.cn>
Co-Authored-By: tangzhuo <ztang@hnu.edu.cn>, zhiyuan_cai <luckyvega.g@gmail.com>

specs/newton/cross-neutron-l2-networking.rst

@@ -557,7 +557,7 @@ References
 
 [3] https://github.com/openstack/networking-l2gw/blob/master/specs/kilo/l2-gateway-api.rst
 
-[4] https://developer.openstack.org/api-ref-networking-v2-ext.html#networks-multi-provider-ext
+[4] https://docs.openstack.org/api-ref/network/v2/index.html#networks-multi-provider-ext
 
 [5] https://docs.openstack.org/mitaka/networking-guide/config-az.html
 

specs/newton/dynamic-pod-binding.rst

@@ -229,8 +229,8 @@ None
 Reference
 ==========
 
-[1] https://developer.openstack.org/api-ref-compute-v2.1.html#showCellCapacities
+[1] https://docs.openstack.org/api-ref-compute-v2.1.html#showCellCapacities
 
-[2] https://developer.openstack.org/api-ref-blockstorage-v2.html#os-vol-pool-v2
+[2] https://docs.openstack.org/api-ref-blockstorage-v2.html#os-vol-pool-v2
 
-[3] https://developer.openstack.org/api-ref-compute-v2.1.html#showinfo
+[3] https://docs.openstack.org/api-ref-compute-v2.1.html#showinfo