Skip rpc nodes in YangSchema::childNodes

Issue: https://tree.taiga.io/project/jktjkt-netconf-cli/issue/133
Change-Id: Id75e71f690730f7f33c639a9b5b37e8683f4637b
diff --git a/tests/yang.cpp b/tests/yang.cpp
index 162a194..a90cb8e 100644
--- a/tests/yang.cpp
+++ b/tests/yang.cpp
@@ -262,6 +262,8 @@
         }
     }
 
+    rpc myRpc {}
+
 })";
 
 namespace std {