PathServlet: Add missing case statements in switch

Change-Id: I5a66fce2f9355e6efb241b03574ad217a74d801c

gitiles-servlet/src/main/java/com/google/gitiles/PathServlet.java

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/PathServlet.java b/gitiles-servlet/src/main/java/com/google/gitiles/PathServlet.java
index 629985d..31e182d 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/PathServlet.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/PathServlet.java
@@ -274,6 +274,9 @@
               TreeJsonData.toJsonData(wr.id, wr.tw, includeSizes, recursive),
               TreeJsonData.Tree.class);
           break;
+        case EXECUTABLE_FILE:
+        case GITLINK:
+        case SYMLINK:
         default:
           res.setStatus(SC_NOT_FOUND);
           break;