Fix ISO no in Array#* and Array#+

The following ISO numbers are incorrect:
```ruby
Array#*      # 15.2.12.5.1
Array#-      # 15.2.12.5.2
```

The following ISO numbers are correct:
```ruby
Array#+      # 15.2.12.5.1
Array#*      # 15.2.12.5.2
```

I made sure above in ISO_IEC_30170_2012(E)_Character_PDF_document.pdf.