database: Define chatlog database location

src/config/files.h

@@ -60,6 +60,7 @@ void files_create_directories(void);
 
 char* files_get_config_path(char *config_base);
 char* files_get_data_path(char *data_base);
+char* files_get_chatlog_database_path(void);
 
 char* files_get_log_file(char *log_file);
 char* files_get_inputrc_file(void);