Update git submodules

* Update docs/submodules/appc.git from branch 'master'
  to 3e71b91278d81f46d7f5f187bfd928edf4b64c89
  - AAPC-1659 removing unused import
    
    removing unused import
    
    Issue-ID: APPC-1659
    Change-Id: Ib7696e4e0fbefe329eda4eb56feb24701f17c4e6
    Signed-off-by: Thugutla Sailakshmi <tsaila10@in.ibm.com>
    
diff --git a/docs/submodules/appc.git b/docs/submodules/appc.git
index 537daa1..3e71b91 160000
--- a/docs/submodules/appc.git
+++ b/docs/submodules/appc.git
@@ -1 +1 @@
-Subproject commit 537daa16e66464b4f252c75bcd3171e63835d951
+Subproject commit 3e71b91278d81f46d7f5f187bfd928edf4b64c89