Update Swarm v1.2.3-rc1

Signed-off-by: Nishant Totla <[email protected]>

library/swarm

@@ -14,4 +14,5 @@
 1.2.0: git://github.com/docker/swarm-library-image@0a35988bfcb18ed0aeb646b511e43e78bc940d07
 1.2.1: git://github.com/docker/swarm-library-image@9d4e009b40520720ceb270408b8078284df9513e
 1.2.2: git://github.com/docker/swarm-library-image@1f9089c40ac560e7b4c878ad6bd7803f4f061e82
+1.2.3-rc1: git://github.com/docker/swarm-library-image@7f1d7c958f92b68cd2b99149daf19fd072852f77
 latest: git://github.com/docker/swarm-library-image@1f9089c40ac560e7b4c878ad6bd7803f4f061e82