Add a warning for mistyped section names.

Change-Id: I267dd6b004d7c59358cb54ba5d9f17fab8d62a59

src/main/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java b/src/main/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java
index 00bbdc1..88a614e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/supermanifest/SuperManifestRefUpdatedListener.java
@@ -195,6 +195,11 @@
     Set<String> wildcardDestinations = new HashSet<>();
     Set<String> sources = new HashSet<>();
 
+    for (String sect : cfg.getSections()) {
+      if (!sect.equals(SECTION_NAME)) {
+        log.warn(name + ".config: ignoring invalid section " + sect);
+      }
+    }
     for (String subsect : cfg.getSubsections(SECTION_NAME)) {
       try {
         ConfigEntry e = newConfigEntry(cfg, subsect);