chore: Add check for principal amount

(cherry picked from commit a76d3827ec)

erpnext/loan_management/doctype/loan_interest_accrual/loan_interest_accrual.py

@@ -236,6 +236,7 @@ def get_term_loans(date, term_loan=None, loan_type=None):
 			AND l.is_term_loan =1
 			AND rs.payment_date <= %s
 			AND rs.is_accrued=0 {0}
+			AND rs.principal_amount > 0
 			AND l.status = 'Disbursed'
 			ORDER BY rs.payment_date""".format(
 			condition