tests: add placeholder for tests on function irc_list_export

tests/unit/plugins/irc/test-irc-list.cpp

@@ -262,6 +262,16 @@ TEST(IrcList, HsignalRedirectListCb)
     /* TODO: write tests */
 }
 
+/*
+ * Tests functions:
+ *   irc_list_export
+ */
+
+TEST(IrcList, Export)
+{
+    /* TODO: write tests */
+}
+
 /*
  * Tests functions:
  *   irc_list_alloc