Update git submodules

* Update docs/submodules/appc.git from branch 'master'
  to 39af688ce0cfc9bc00201d283ae101a129cf750a
  - Sonar Fix: LookupServer.java
    
    Fixed sonar issues across this file
    
    Issue-ID: APPC-1739
    Change-Id: Iabbaada720d8b3f2ee3916a0d663b90f8fe23bcb
    Signed-off-by: Arundathi Patil <arundpil@in.ibm.com>
    
diff --git a/docs/submodules/appc.git b/docs/submodules/appc.git
index b43aa4f..39af688 160000
--- a/docs/submodules/appc.git
+++ b/docs/submodules/appc.git
@@ -1 +1 @@
-Subproject commit b43aa4f328c387cd433cfc6d79643f5f7dc34fc1
+Subproject commit 39af688ce0cfc9bc00201d283ae101a129cf750a