Set HTML_TIMESTAMP to NO to make build reproducible

Change-Id: I56cce5cda0621f5e9f1c28aaad4646e9e267d17d
diff --git a/Doxyfile.codec.in b/Doxyfile.codec.in
index 307e3e1..88f0d27 100644
--- a/Doxyfile.codec.in
+++ b/Doxyfile.codec.in
@@ -891,7 +891,7 @@
 # page will contain the date and time when the page was generated. Setting
 # this to NO can help when comparing the output of multiple runs.
 
-HTML_TIMESTAMP         = YES
+HTML_TIMESTAMP         = NO
 
 # If the HTML_ALIGN_MEMBERS tag is set to YES, the members of classes,
 # files or namespaces will be aligned in HTML using tables. If set to