[CBRD-25345] check invalid ACL entry

[kisoo-han]

http://jira.cubrid.org/browse/CBRD-25345

Description

• broker ACL list example

  dbname1:dbuser1:READIP.txt
  *:dba:READIP.txt
  

Remarks: just add check invalid ACL entry whether it start with the following characters:

1. '[' (for section name)
2. '*' (for database name wild card)
3. alphabet (for valid database name)

• anything else could be invalid
• please comment, if you have any other opinion