In times like these, J B Weld is your best friend!
J B Weld is a cold weld product that can withstand ~500°F which should patch this leak just fine.
First squeeze out some of the 'Steel' into a small cup or paper towel.
Next squeeze an equal amount of the 'Hardener'.
Mix up the 'Steel' and 'Hardener'
Apply!
I am letting the J B Weld set for about 2 days just to me sure that everything is good and bonded.