Fix balance_uninvoiced description (#399)

Author: bbiggerr

openapi.yaml

@@ -15232,7 +15232,7 @@ components:
           readOnly: true
           description: >
             This Account's current estimated invoice in US dollars. This is not
-            your final invoice balance. Bandwidth charges are not included in
+            your final invoice balance. Transfer charges are not included in
             the estimate.
           example: 145
           x-linode-cli-display: 4