Set environment variable "DEBUG=1" when "--debug" is set for F::Q

[Bruce Schuck]

John and team,

While responding to an issue reported to Finance::Quote when a user 
could not get currency rates after upgrading his OS to Ubuntu 25.10, I 
had an idea.

The user included output from:

gnucash-cli --debug --quotes dump currency CHF EUR

Of which the only output from F::Q is:

18:11:51 INFO <gnc.price-quotes> [GncQuotesImpl::query_fq] Query JSON: {
"defaultcurrency": "CHF",
"currency": {
"EUR": ""
}
}

Would it be possible that if a user has both "--debug" and "--quotes", 
that "DEBUG=1" is set in the environment before F::Q is called? This 
will turn on debugging in the F::Q methods that are using the 
"Smart::Comments" module for debugging.

Thank you.

Bruce S