Bump kOptionsVersion to bust the cache

Signed-off-by: Otto van der Schaaf <oschaaf@we-amp.com>
diff --git a/net/instaweb/rewriter/public/rewrite_options.h b/net/instaweb/rewriter/public/rewrite_options.h
index 3913dd8..21dac01 100644
--- a/net/instaweb/rewriter/public/rewrite_options.h
+++ b/net/instaweb/rewriter/public/rewrite_options.h
@@ -596,7 +596,7 @@
   // This version number should be incremented if any default-values
   // are changed, either in an Add*Property() call or via
   // options->set_default.
-  static constexpr int kOptionsVersion = 14;
+  static constexpr int kOptionsVersion = 15;
 
   // Number of bytes used for signature hashing.
   static constexpr int kHashBytes = 20;