Bump version file on docs

Author: silvakid

doc/doxygen.cfg

@@ -60,7 +60,7 @@ PROJECT_NAME           = "MySQL Connector/C++"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2.0.3
+PROJECT_NUMBER         = 2.0.4
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a