Tab in name output for JSON

[Peter Naulls]

This is a return to an issue I mentioned quite some time ago; there were some 
questionable characters in the model name output.

https://gitlab.freedesktop.org/mobile-broadband/libqmi/-/merge_requests/159

This results in a tab character in the JSON output too:

"model":"EM12-AW\t"

Now, you could certainly argue that this doesn't need to be fixed or 
"corrected", but I think it's worth mentioning for completeness, since
the rogue tab is at odds with the rest of the strings.