Bug 11509: (trivial rmaint followup) wrong parameter count

Bug 11509: (trivial rmaint followup) wrong parameter count

While adding the --help and -h switches I forgot to change to arguments
count validation so that one can actually use those parameters (i.e.
koha-create should accept being invoked with only one parameter).

This patch just changes the minimum parateres required from 2 to 1.

To reproduce:
- Run 'koha-create --help' from master
=> Usage information is printed BUT ALSO an "Error: wrong parameters"
   message
- Apply the patch and
- Run 'koha-create --help'
=> Usage informatio it printed and no error message.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>