Fixes #6766 - Pagination is failing

```
# hammer activation-key list --organization-label='ACME_Corporation' --page=1 --per-page=2
---|--------|----------------|-----------------------|-------------
ID | NAME   | CONSUMED       | LIFECYCLE ENVIRONMENT | CONTENT VIEW
---|--------|----------------|-----------------------|-------------
5  | actkey | 0 of Unlimited |                       |             
8  | ak1234 | 0 of Unlimited |                       | cv1         
---|--------|----------------|-----------------------|-------------
List next page? (Y/n): Y
Error: can't convert Fixnum into String
```

Applicable for any list command
I'm afraid `|| 1` won't work.
```
nil.to_i
=> 0
```
```
0 || 1
=> 0
```
Shouldn't we rather do `(self.option_page || 1).to_i` ?