fix: supply a mapping to DESCRIPTION format string

cash/admin.py

@@ -32,7 +32,7 @@ class AccountAdmin(admin.ModelAdmin):
 	def save_model(self, request, obj, form, change):
 		PAYOUT_SUBJECT = ugettext_noop('Payout')
 		DEPOSIT_SUBJECT = ugettext_noop('Deposit')
-		DESC = ugettext_noop('Authorized by %(first)s %(last)s')
+		DESCRIPTION = ugettext_noop('Authorized by %(first)s %(last)s')
 
 		amount = form.cleaned_data['credit_change']
 
@@ -44,8 +44,9 @@ class AccountAdmin(admin.ModelAdmin):
 			else:
 				subject = PAYOUT_SUBJECT
 
-			obj.change_credit(amount, subject, DESC % (request.user.first_name,
-			                                           request.user.last_name))
+			desc = DESCRIPTION % {'first': request.user.first_name,
+			                      'last': request.user.last_name}
+			obj.change_credit(amount, subject, desc)
 
 
 class ProductBarcodeInline(admin.TabularInline):