Module & Sub module grammar issue fix

Change-Id: Ia90b90510233195c5eab7402ebe790014ce137d1
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
index bc8ee02..d65af88 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
@@ -79,7 +79,7 @@
         YangModule yangModule = new YangModule();
         yangModule.setName(identifier);
 
-        if (ctx.moduleBody(0).moduleHeaderStatement().yangVersionStatement() == null) {
+        if (ctx.moduleBody().moduleHeaderStatement().yangVersionStatement() == null) {
             yangModule.setVersion((byte) 1);
         }