[whatwg] SQL API - Small editorial fix

[Brady Eidson]

There are 6 steps for the SQLTransaction.executeSql() call before the  
statement is queued up.

Step 5 says:
"If the Database object has an expected version that is neither the  
empty string nor the actual version of the database, then mark the  
statement as bogus (Error code 2)"

Now that executeSql() is on the SQLTransaction object and not the  
Database object, I think some context was lost here.
It's pretty obvious that we mean "the Database object this  
SQLTransaction was created with", but perhaps the spec should state  
that explicitly for those who haven't been following its evolution  
like we have  :)

Thanks,
~Brady