Invalid Command format message does not appear for delClient

[dlimyy]

Steps to reproduce bug:

delClient

Expected Output:

Invalid command format! 
delClient: Deletes the client identified by the index number used in the displayed client list.
Parameters: INDEX (must be a positive integer)
Example: delClient i/1

Actual Output:

Compared to addClient where the invalid command format appears when only addClient is entered, delClient does not display the invalid command format message when only delClient is entered. The invalid command format message for delClient only shows up when the i/ prefix of delClient is included.