Disable timestamping in Doxygen

So the output is reproducible.

Signed-off-by: Thiago Macieira <thiago.macieira@intel.com>
diff --git a/Doxyfile b/Doxyfile
index a23aa35..a7263c2 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -23,12 +23,11 @@
                          *.c \
                          *.dox
 EXCLUDE_PATTERNS       = *_p.h
-IMAGE_PATH             = pics
 STRIP_CODE_COMMENTS    = NO
 REFERENCED_BY_RELATION = YES
 IGNORE_PREFIX          = cbor_ \
                          Cbor
-HTML_TIMESTAMP         = YES
+HTML_TIMESTAMP         = NO
 GENERATE_HTMLHELP      = YES
 GENERATE_CHI           = YES
 BINARY_TOC             = YES