sangarbe

Seedtag Adapter: fix required content-type header on http calls

1

We were missing to add the required content-type headers to request Seedtag server-to-server endpoint. This situation lead to unparsed body payloads for the first integrations.

### 🔧 Type of changes - [x] new bid adapter - [ ] bid adapter update - [ ] new feature - [ ] new analytics adapter - [ ]...