Add test for identityref invalid module

Found via code coverage.

Change-Id: I1e2080011d959fef26307ced22894282766e6d6c
diff --git a/tests/leaf_editing.cpp b/tests/leaf_editing.cpp
index 76e26d3..1a55fa1 100644
--- a/tests/leaf_editing.cpp
+++ b/tests/leaf_editing.cpp
@@ -568,6 +568,12 @@
             input = "set mod:foodIdentRef identityBLABLA";
         }
 
+        SECTION("identity with non-existing module")
+        {
+            expectedError = "Invalid module name";
+            input = "set mod:foodIdentRef xd:haha";
+        }
+
         SECTION("setting identities with wrong bases")
         {
             SECTION("set mod:foodIdentRef mod:vehicle")