doc/doxygen: turn doxygen quiet

doc/doxygen/doxygen.cfg

@@ -639,7 +639,7 @@ CITE_BIB_FILES         =
 # The QUIET tag can be used to turn on/off the messages that are generated
 # by doxygen. Possible values are YES and NO. If left blank NO is used.
 
-QUIET                  = NO
+QUIET                  = YES
 
 # The WARNINGS tag can be used to turn on/off the warning messages that are
 # generated by doxygen. Possible values are YES and NO. If left blank