security+tools: Allow user to explicitly specify the cert name prefix before 'KEY' component in ndnsec-certgen

Change-Id: I71e137e89b5ab0cd5db7001b39ff76c22a448bd2
Refs: #1659
diff --git a/docs/doxygen.conf.in b/docs/doxygen.conf.in
index 24b3de7..7b79b1e 100644
--- a/docs/doxygen.conf.in
+++ b/docs/doxygen.conf.in
@@ -1888,7 +1888,7 @@
 # The default value is: NO.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-MACRO_EXPANSION        = NO
+MACRO_EXPANSION        = YES
 
 # If the EXPAND_ONLY_PREDEF and MACRO_EXPANSION tags are both set to YES then
 # the macro expansion is limited to the macros specified with the PREDEFINED and