Fix doxygen.cfg

Add JWT_EXPORT and DEPRECATED macros to the PREDEFINED tag in
doxygen.cfg file.

doxygen.cfg

@@ -2037,7 +2037,7 @@ INCLUDE_FILE_PATTERNS  =
 # recursively expanded use the := operator instead of the = operator.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-PREDEFINED             = _DOXYGEN
+PREDEFINED             = _DOXYGEN JWT_EXPORT= DEPRECATED(x)=x __attribute__(x)=
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The