Fix content type header

[patrickszeleczki]

No description provided.

[github-actions]

Code coverage summary

Note:

• Prebid team doesn't anticipate tests covering code paths that might result in marshal and unmarshal errors
• Coverage summary encompasses all commits leading up to the latest one, b57a08a

connatix

Refer here for heat map coverage report

github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:23:	Builder			80.0%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:35:	MakeRequests		66.7%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:81:	MakeBids		80.0%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:121:	validateAndBuildImpExt	66.7%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:134:	validateConnatixExt	66.7%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:143:	splitRequests		90.9%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:185:	buildRequestImp		66.7%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:233:	buildDisplayManageVer	55.6%
github.com/prebid/prebid-server/v2/adapters/connatix/connatix.go:251:	getBidType		100.0%
total:									(statements)		74.5%