wallet_api.json has 4 missing commas, manual fix.

wallet_api.json has 4 missing commas.

- wallet_import_multibit
- wallet_import_electrum
- wallet_import_armory
- wallet_import_bitcoin

the

"type" : "filename" 

part misses a comma at the end.
Merge pull request #265 from mauritso1/patch-1

wallet_api.json has 4 missing commas, manual fix.