Releasing concurrent map access fix

Change-Id: I4189ba84b05cb0d142451fcd11c476a00e36ce97
diff --git a/releases/voltha-2.6 b/releases/voltha-2.6
index 123e56a..7b85f74 100644
--- a/releases/voltha-2.6
+++ b/releases/voltha-2.6
@@ -4,7 +4,7 @@
 # Source this file before running ./voltha up to install the VOLTHA 2.5.0 release
 
 export VOLTHA_CHART_VERSION=2.7.2
-export VOLTHA_BBSIM_CHART_VERSION=4.1.5
+export VOLTHA_BBSIM_CHART_VERSION=4.1.6
 export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.7.1
 export VOLTHA_ADAPTER_OPEN_ONU_CHART_VERSION=2.6.9
 export BBSIM_SADIS_SERVER_CHART_VERSION=0.0.3