Add dummy serialVersionUID in SmallResource to prevent Eclipse warning

Change-Id: I19683b46ee4e0bb809852622d7866def2ca3b9a6
diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/resources/SmallResource.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/resources/SmallResource.java
index 196beeb..d057269 100644
--- a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/resources/SmallResource.java
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/resources/SmallResource.java
@@ -23,6 +23,7 @@
 import javax.servlet.http.HttpServletResponse;
 
 public final class SmallResource extends Resource {
+  private static final long serialVersionUID = 1L;
   private final byte[] data;
   private String contentType;
   private String characterEncoding;