Using latest openolt-adapter chart in voltha-2.4 release

Change-Id: I97df4c21bd01cff1907ef31b19044318135af007
diff --git a/releases/voltha-2.4 b/releases/voltha-2.4
index d258623..4abddaf 100644
--- a/releases/voltha-2.4
+++ b/releases/voltha-2.4
@@ -5,7 +5,7 @@
 
 export VOLTHA_CHART_VERSION=2.5.4
 export VOLTHA_BBSIM_CHART_VERSION=3.0.29
-export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.5.4
+export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.5.5
 export VOLTHA_ADAPTER_OPEN_ONU_CHART_VERSION=2.4.2
 export ONOS_CLASSIC_CHART_VERSION=0.1.1
 export RADIUS_CHART_VERSION=1.0.0