MINOR: server: respect warning and alert semantic

Error codes ERR_WARN and ERR_ALERT are used to signal that the error
given is of the corresponding level. All errors are displayed as ALERT
in the display_parser_err() function.

Differentiate the display level based on the error code. If both
ERR_WARN and ERR_ALERT are used, ERR_ALERT is given priority.
1 file changed